highs-sys 1.14.2

#include <stdio.h>
#include <stdlib.h>

#include "HCheckConfig.h"
#include "interfaces/highs_c_api.h"
// Force asserts to be checked always.
#undef NDEBUG
#include <assert.h>
#include <math.h>
#include <string.h>

const HighsInt dev_run = 0;
const double double_equal_tolerance = 1e-5;

void checkGetCallbackDataOutPointer(const HighsCallbackDataOut* data_out,
                                    const char* name, HighsInt valid) {
  const void* name_p = Highs_getCallbackDataOutItem(data_out, name);
  if (valid) {
    if (!name_p)
      printf("checkGetCallbackDataOutItem fail for %s (valid = %d)\n", name,
             (int)valid);
    assert(name_p);
  } else {
    if (name_p)
      printf("checkGetCallbackDataOutItem fail for %s (valid = %d)\n", name,
             (int)valid);
    assert(!name_p);
  }
}

void checkGetCallbackDataOutHighsInt(const HighsCallbackDataOut* data_out,
                                     const char* name, HighsInt value) {
  const void* name_p = Highs_getCallbackDataOutItem(data_out, name);
  if (!name_p) {
    printf("checkGetCallbackDataOutItem fail for %s\n", name);
    assert(name_p);
  } else {
    HighsInt check_value = *(HighsInt*)(name_p);
    HighsInt value_ok = check_value == value;
    if (!value_ok)
      printf(
          "checkGetCallbackDataOutItem fail for %s (%d = check_value != value "
          "= %d)\n",
          name, (int)check_value, (int)value);
    assert(value_ok);
  }
}

void checkGetCallbackDataOutInt(const HighsCallbackDataOut* data_out,
                                const char* name, int value) {
  const void* name_p = Highs_getCallbackDataOutItem(data_out, name);
  if (!name_p) {
    printf("checkGetCallbackDataOutInt fail for %s\n", name);
    assert(name_p);
  } else {
    int check_value = *(int*)(name_p);
    int value_ok = check_value == value;
    if (!value_ok)
      printf(
          "checkGetCallbackDataOutInt fail for %s (%d = check_value != value = "
          "%d)\n",
          name, check_value, value);
    assert(value_ok);
  }
}

void checkGetCallbackDataOutInt64(const HighsCallbackDataOut* data_out,
                                  const char* name, int64_t value) {
  const void* name_p = Highs_getCallbackDataOutItem(data_out, name);
  if (!name_p) {
    printf("checkGetCallbackDataOutInt64 fail for %s\n", name);
    assert(name_p);
  } else {
    int64_t check_value = *(int*)(name_p);
    int value_ok = check_value == value;
    if (!value_ok)
      printf(
          "checkGetCallbackDataOutInt64 fail for %s (%d = check_value != value "
          "= %d)\n",
          name, (int)check_value, (int)value);
    assert(value_ok);
  }
}

void checkGetCallbackDataOutDouble(const HighsCallbackDataOut* data_out,
                                   const char* name, double value) {
  const void* name_p = Highs_getCallbackDataOutItem(data_out, name);
  if (!name_p) {
    printf("checkGetCallbackDataOutDouble fail for %s\n", name);
    assert(name_p);
  } else {
    double check_value = *(double*)(name_p);
    double value_ok = check_value == value;
    if (!value_ok)
      printf(
          "checkGetCallbackDataOutDouble fail for %s (%g = check_value != "
          "value = %g)\n",
          name, check_value, value);
    assert(value_ok);
  }
}

static void userCallback(const int callback_type, const char* message,
                         const HighsCallbackDataOut* data_out,
                         HighsCallbackDataIn* data_in,
                         void* user_callback_data) {
  // Extract the double value pointed to from void* user_callback_data
  const double local_callback_data =
      user_callback_data == NULL ? -1 : *(double*)user_callback_data;

  if (callback_type == kHighsCallbackLogging) {
    if (dev_run)
      printf("userCallback(%11.4g): %s\n", local_callback_data, message);
  } else if (callback_type == kHighsCallbackMipImprovingSolution) {
    // Test the accessor function for data_out
    //
    // Check that passing an valid name returns a non-null pointer,
    // and that the corresponding value is the same as obtained using
    // the struct
    const void* objective_function_value_p = Highs_getCallbackDataOutItem(
        data_out, kHighsCallbackDataOutObjectiveFunctionValueName);
    assert(objective_function_value_p);
    double objective_function_value = *(double*)(objective_function_value_p);
    assert(objective_function_value == data_out->objective_function_value);
    if (dev_run)
      printf("userCallback(%11.4g): improving solution with objective = %g\n",
             local_callback_data, objective_function_value);
    // Now test all more simply
    checkGetCallbackDataOutInt(data_out, kHighsCallbackDataOutLogTypeName, 1);
    checkGetCallbackDataOutDouble(
        data_out, kHighsCallbackDataOutRunningTimeName, data_out->running_time);
    checkGetCallbackDataOutHighsInt(
        data_out, kHighsCallbackDataOutSimplexIterationCountName,
        data_out->simplex_iteration_count);
    checkGetCallbackDataOutHighsInt(data_out,
                                    kHighsCallbackDataOutIpmIterationCountName,
                                    data_out->ipm_iteration_count);
    checkGetCallbackDataOutHighsInt(data_out,
                                    kHighsCallbackDataOutPdlpIterationCountName,
                                    data_out->pdlp_iteration_count);
    checkGetCallbackDataOutDouble(
        data_out, kHighsCallbackDataOutObjectiveFunctionValueName,
        data_out->objective_function_value);
    checkGetCallbackDataOutInt64(data_out,
                                 kHighsCallbackDataOutMipNodeCountName,
                                 data_out->mip_node_count);
    checkGetCallbackDataOutDouble(data_out,
                                  kHighsCallbackDataOutMipPrimalBoundName,
                                  data_out->mip_primal_bound);
    checkGetCallbackDataOutDouble(data_out,
                                  kHighsCallbackDataOutMipDualBoundName,
                                  data_out->mip_dual_bound);
    checkGetCallbackDataOutDouble(data_out, kHighsCallbackDataOutMipGapName,
                                  data_out->mip_gap);
    // Cutpool data structure is not assigned, so num_col, num_cut and
    // num_nz are unassigned
    //    checkGetCallbackDataOutHighsInt(data_out,
    //				    kHighsCallbackDataOutCutpoolNumColName, 0);
    //    checkGetCallbackDataOutHighsInt(data_out,
    //				    kHighsCallbackDataOutCutpoolNumCutName, 0);
    //    checkGetCallbackDataOutHighsInt(data_out,
    //				    kHighsCallbackDataOutCutpoolNumNzName, 0);

    // Check that passing an unrecognised name returns NULL
    const void* foo_p = Highs_getCallbackDataOutItem(data_out, "foo");
    assert(!foo_p);
    // Check that passing the name of an assigned vector returns
    // non-NULL, and that the corresponding value is the same as
    // obtained using the struct
    const void* mip_solution_void_p = Highs_getCallbackDataOutItem(
        data_out, kHighsCallbackDataOutMipSolutionName);
    assert(mip_solution_void_p);
    double mip_solution0 = *(double*)(mip_solution_void_p);
    assert(mip_solution0 == *(data_out->mip_solution));
    if (dev_run)
      printf("userCallback(%11.4g): improving solution with value[0] = %g\n",
             local_callback_data, mip_solution0);
    // Cutpool data structure is not assigned, so cannot check that
    // passing names of the unassigned vectors returns NULL
    //    assert(!Highs_getCallbackDataOutItem(data_out,
    //    kHighsCallbackDataOutCutpoolStartName));
    //    assert(!Highs_getCallbackDataOutItem(data_out,
    //    kHighsCallbackDataOutCutpoolIndexName));
    //    assert(!Highs_getCallbackDataOutItem(data_out,
    //    kHighsCallbackDataOutCutpoolValueName));
    //    assert(!Highs_getCallbackDataOutItem(data_out,
    //    kHighsCallbackDataOutCutpoolLowerName));
    //    assert(!Highs_getCallbackDataOutItem(data_out,
    //    kHighsCallbackDataOutCutpoolUpperName));
  } else if (callback_type == kHighsCallbackMipLogging) {
    if (dev_run)
      printf("userCallback(%11.4g): MIP logging\n", local_callback_data);
    data_in->user_interrupt = 1;
  } else if (callback_type == kHighsCallbackMipInterrupt) {
    if (dev_run)
      printf("userCallback(%11.4g): MIP interrupt\n", local_callback_data);
    data_in->user_interrupt = 1;
  }
}

HighsInt highsIntArraysEqual(const HighsInt dim, const HighsInt* array0,
                             const HighsInt* array1) {
  for (HighsInt ix = 0; ix < dim; ix++)
    if (array0[ix] != array1[ix]) return 0;
  return 1;
}

HighsInt doubleArraysEqual(const double dim, const double* array0,
                           const double* array1) {
  for (HighsInt ix = 0; ix < dim; ix++)
    if (array0[ix] != array1[ix]) return 0;
  return 1;
}

void assertDoubleValuesEqual(const char* name, const double is,
                             const double should_be) {
  const double dl = fabs(is - should_be);
  if (dl > double_equal_tolerance) {
    printf("Value %s = %g differs from %g by %g but should be equal\n", name,
           is, should_be, dl);
    assert(1 == 0);
  }
}

void assertIntValuesEqual(const char* name, const HighsInt is,
                          const HighsInt should_be) {
  if (is != should_be) {
    printf("Value %s = %" HIGHSINT_FORMAT " should be %" HIGHSINT_FORMAT "\n",
           name, is, should_be);
    assert(1 == 0);
  }
}

void assertLogical(const char* name, const HighsInt is) {
  if (is == 0) {
    printf("Value %s = %" HIGHSINT_FORMAT " should not be 0\n", name, is);
    assert(1 == 0);
  }
}

void createBlendingLp(void* highs) {
  // Special variant of the blending LP, with redundant constraint so
  // that LP is reduced by presolve - but not to empty!
  const double inf = Highs_getInfinity(highs);

  HighsInt num_col = 2;
  HighsInt num_row = 3;
  HighsInt num_nz = 6;
  HighsInt sense = -1;
  double col_cost[2] = {8, 10};
  double col_lower[2] = {0, 0};
  double col_upper[2] = {inf, inf};
  double row_lower[3] = {-inf, -inf, -inf};
  double row_upper[3] = {500, 120, 210};
  HighsInt a_index[6] = {0, 1, 0, 1, 0, 1};
  double a_value[6] = {0.5, 0.5, 0.3, 0.5, 0.7, 0.5};
  HighsInt a_start[3] = {0, 2, 4};
  Highs_addVars(highs, num_col, col_lower, col_upper);
  Highs_changeColsCostByRange(highs, 0, num_col - 1, col_cost);
  Highs_addRows(highs, num_row, row_lower, row_upper, num_nz, a_start, a_index,
                a_value);
  Highs_changeObjectiveSense(highs, sense);
}

// Test methods
void versionApi() {
  if (dev_run) {
    printf("HiGHS version %s\n", Highs_version());
    printf("HiGHS version major %" HIGHSINT_FORMAT "\n", Highs_versionMajor());
    printf("HiGHS version minor %" HIGHSINT_FORMAT "\n", Highs_versionMinor());
    printf("HiGHS version patch %" HIGHSINT_FORMAT "\n", Highs_versionPatch());
    printf("HiGHS githash: %s\n", Highs_githash());
  }
}

void minimalApiLp() {
  // This illustrates the use of Highs_call, the simple C interface to
  // HiGHS. It's designed to solve the general LP problem
  //
  // Min c^Tx subject to L <= Ax <= U; l <= x <= u
  //
  // where A is a matrix with m rows and n columns
  //
  // The scalar n is num_col
  // The scalar m is num_row
  //
  // The vector c is col_cost
  // The vector l is col_lower
  // The vector u is col_upper
  // The vector L is row_lower
  // The vector U is row_upper
  //
  // The matrix A is represented in packed column-wise form: only its
  // nonzeros are stored
  //
  // * The number of nonzeros in A is num_nz
  //
  // * The row indices of the nonnzeros in A are stored column-by-column
  // in a_index
  //
  // * The values of the nonnzeros in A are stored column-by-column in
  // a_value
  //
  // * The position in a_index/a_value of the index/value of the first
  // nonzero in each column is stored in a_start
  //
  // Note that a_start[0] must be zero
  //
  // After a successful call to Highs_call, the primal and dual
  // solution, and the simplex basis are returned as follows
  //
  // The vector x is col_value
  // The vector Ax is row_value
  // The vector of dual values for the variables x is col_dual
  // The vector of dual values for the variables Ax is row_dual
  // The basic/nonbasic status of the variables x is col_basis_status
  // The basic/nonbasic status of the variables Ax is row_basis_status
  //
  // The status of the solution obtained is model_status
  //
  // To solve maximization problems, the values in c must be negated
  //
  // The use of Highs_lpCall is illustrated for the LP
  //
  // Min    f  = 2x_0 + 3x_1
  // s.t.                x_1 <= 6
  //       10 <=  x_0 + 2x_1 <= 14
  //        8 <= 2x_0 +  x_1
  // 0 <= x_0 <= 3; 1 <= x_1

  const HighsInt num_col = 2;
  const HighsInt num_row = 3;
  const HighsInt num_nz = 5;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;

  // Define the column costs, lower bounds and upper bounds
  double col_cost[2] = {2.0, 3.0};
  double col_lower[2] = {0.0, 1.0};
  double col_upper[2] = {3.0, 1.0e30};
  // Define the row lower bounds and upper bounds
  double row_lower[3] = {-1.0e30, 10.0, 8.0};
  double row_upper[3] = {6.0, 14.0, 1.0e30};
  // Define the constraint matrix column-wise
  HighsInt a_start[2] = {0, 2};
  HighsInt a_index[5] = {1, 2, 0, 1, 2};
  double a_value[5] = {1.0, 2.0, 1.0, 2.0, 1.0};

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  double* col_dual = (double*)malloc(sizeof(double) * num_col);
  double* row_value = (double*)malloc(sizeof(double) * num_row);
  double* row_dual = (double*)malloc(sizeof(double) * num_row);

  HighsInt* col_basis_status = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* row_basis_status = (HighsInt*)malloc(sizeof(HighsInt) * num_row);

  HighsInt model_status;

  HighsInt return_status =
      Highs_lpCall(num_col, num_row, num_nz, a_format, sense, offset, col_cost,
                   col_lower, col_upper, row_lower, row_upper, a_start, a_index,
                   a_value, col_value, col_dual, row_value, row_dual,
                   col_basis_status, row_basis_status, &model_status);

  assert(return_status == kHighsStatusOk);

  if (dev_run) {
    printf("Run status = %" HIGHSINT_FORMAT "; Model status = %" HIGHSINT_FORMAT
           "\n",
           return_status, model_status);

    HighsInt i;
    if (model_status == kHighsModelStatusOptimal) {
      double objective_value = 0;
      // Report the column primal and dual values, and basis status
      for (i = 0; i < num_col; i++) {
        printf("Col%" HIGHSINT_FORMAT
               " = %lf; dual = %lf; status = %" HIGHSINT_FORMAT "; \n",
               i, col_value[i], col_dual[i], col_basis_status[i]);
        objective_value += col_value[i] * col_cost[i];
      }
      // Report the row primal and dual values, and basis status
      for (i = 0; i < num_row; i++) {
        printf("Row%" HIGHSINT_FORMAT
               " = %lf; dual = %lf; status = %" HIGHSINT_FORMAT "; \n",
               i, row_value[i], row_dual[i], row_basis_status[i]);
      }
      printf("Optimal objective value = %g\n", objective_value);
    }
  }

  free(col_value);
  free(col_dual);
  free(row_value);
  free(row_dual);
  free(col_basis_status);
  free(row_basis_status);
}

void minimalApiMip() {
  // The use of Highs_mipCall is illustrated for the MIP
  //
  // Min    f  = -3x_0 - 2x_1 - x_2
  // s.t.          x_0 +  x_1 + x_2 <=  7
  //              4x_0 + 2x_1 + x_2  = 12
  //              x_0 >=0; x_1 >= 0; x_2 binary

  const HighsInt num_col = 3;
  const HighsInt num_row = 2;
  const HighsInt num_nz = 6;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;

  // Define the column costs, lower bounds and upper bounds
  double col_cost[3] = {-3.0, -2.0, -1.0};
  double col_lower[3] = {0.0, 0.0, 0.0};
  double col_upper[3] = {1.0e30, 1.0e30, 1.0};
  // Define the row lower bounds and upper bounds
  double row_lower[2] = {-1.0e30, 12.0};
  double row_upper[2] = {7.0, 12.0};
  // Define the constraint matrix column-wise
  HighsInt a_start[3] = {0, 2, 4};
  HighsInt a_index[6] = {0, 1, 0, 1, 0, 1};
  double a_value[6] = {1.0, 4.0, 1.0, 2.0, 1.0, 1.0};

  // Give an illegal value to an entry in integrality
  HighsInt integrality[3] = {kHighsVarTypeContinuous, kHighsVarTypeContinuous,
                             -1};

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  double* row_value = (double*)malloc(sizeof(double) * num_row);

  HighsInt model_status;
  HighsInt return_status;

  return_status = Highs_mipCall(
      num_col, num_row, num_nz, a_format, sense, offset, col_cost, col_lower,
      col_upper, row_lower, row_upper, a_start, a_index, a_value, integrality,
      col_value, row_value, &model_status);
  // Should return error, with model status not set
  assert(return_status == kHighsStatusError);
  assert(model_status == kHighsModelStatusNotset);

  // Correct integrality
  integrality[num_col - 1] = kHighsVarTypeInteger;

  return_status = Highs_mipCall(
      num_col, num_row, num_nz, a_format, sense, offset, col_cost, col_lower,
      col_upper, row_lower, row_upper, a_start, a_index, a_value, integrality,
      col_value, row_value, &model_status);
  // Should return OK
  assert(return_status == kHighsStatusOk);

  if (dev_run) {
    printf("Run status = %" HIGHSINT_FORMAT "; Model status = %" HIGHSINT_FORMAT
           "\n",
           return_status, model_status);

    HighsInt i;
    if (model_status == kHighsModelStatusOptimal) {
      double objective_value = 0;
      // Report the column primal values
      for (i = 0; i < num_col; i++) {
        printf("Col%" HIGHSINT_FORMAT " = %lf; \n", i, col_value[i]);
        objective_value += col_value[i] * col_cost[i];
      }
      // Report the row primal values
      for (i = 0; i < num_row; i++) {
        printf("Row%" HIGHSINT_FORMAT " = %lf; \n", i, row_value[i]);
      }
      printf("Optimal objective value = %g\n", objective_value);
    }
  }

  free(col_value);
  free(row_value);
}

void minimalApiQp() {
  // Test solving the problem qjh
  //
  // minimize -x_2 - 3x_3 + (1/2)(2x_1^2 - 2x_1x_3 + 0.2x_2^2 + 2x_3^2)
  //
  // subject to x_1 + x_3 <= 2; x>=0
  const double inf = 1e30;
  HighsInt num_col = 3;
  HighsInt num_row = 1;
  HighsInt num_nz = 2;
  HighsInt q_num_nz = 4;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt q_format = kHighsHessianFormatTriangular;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;
  double col_cost[3] = {0.0, -1.0, -3.0};
  double col_lower[3] = {-inf, -inf, -inf};
  double col_upper[3] = {inf, inf, inf};
  double row_lower[1] = {-inf};
  double row_upper[1] = {2};
  HighsInt a_start[3] = {0, 1, 1};
  HighsInt a_index[2] = {0, 0};
  double a_value[2] = {1.0, 1.0};
  HighsInt q_start[3] = {0, 2, 3};
  HighsInt q_index[4] = {0, 2, 1, 2};
  double q_value[4] = {2.0, -1.0, 0.2, 2.0};

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  HighsInt model_status;
  HighsInt return_status = Highs_qpCall(
      num_col, num_row, num_nz, q_num_nz, a_format, q_format, sense, offset,
      col_cost, col_lower, col_upper, row_lower, row_upper, a_start, a_index,
      a_value, q_start, q_index, q_value, col_value, NULL, NULL, NULL, NULL,
      NULL, &model_status);
  assert(return_status == kHighsStatusOk);
  assertIntValuesEqual("Model status for QP qph", model_status,
                       kHighsModelStatusOptimal);
  double required_x[3] = {0.5, 5.0, 1.5};
  if (dev_run) {
    for (HighsInt iCol = 0; iCol < num_col; iCol++) {
      printf("x%d1 = %g\n", (int)iCol, col_value[iCol]);
      assertDoubleValuesEqual("Solution value for QP qph", col_value[iCol],
                              required_x[iCol]);
    }
  }
  free(col_value);
}

void minimalApiIllegalLp() {
  const double inf = 1e30;
  HighsInt num_col = 2;
  HighsInt num_row = 1;
  HighsInt num_nz = 2;
  HighsInt a_format = kHighsMatrixFormatRowwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;
  double col_cost[2] = {0.0, -1.0};
  double col_lower[2] = {-inf, -inf};
  double col_upper[2] = {inf, inf};
  double row_lower[1] = {-inf};
  double row_upper[1] = {2};
  HighsInt a_start[1] = {0};
  HighsInt a_index[2] = {0, -1};  // Illegal index
  double a_value[2] = {1.0, 1.0};

  HighsInt model_status;
  HighsInt return_status =
      Highs_lpCall(num_col, num_row, num_nz, a_format, sense, offset, col_cost,
                   col_lower, col_upper, row_lower, row_upper, a_start, a_index,
                   a_value, NULL, NULL, NULL, NULL, NULL, NULL, &model_status);
  // Should return error, with model status not set
  assert(return_status == kHighsStatusError);
  assert(model_status == kHighsModelStatusNotset);
}

void testNames() {
  void* highs = Highs_create();

  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);

  createBlendingLp(highs);

  HighsInt return_status;

  const HighsInt num_col = 2;
  const HighsInt num_row = 3;
  assert(num_col == Highs_getNumCols(highs));
  assert(num_row == Highs_getNumRows(highs));

  char* col_prefix = "Col";
  char* row_prefix = "Row";
  // Check index out of bounds

  return_status = Highs_passColName(highs, -1, col_prefix);
  assert(return_status == kHighsStatusError);
  return_status = Highs_passRowName(highs, -1, row_prefix);
  assert(return_status == kHighsStatusError);
  return_status = Highs_passColName(highs, num_col, col_prefix);
  assert(return_status == kHighsStatusError);
  return_status = Highs_passRowName(highs, num_row, row_prefix);
  assert(return_status == kHighsStatusError);

  // Define all column names to be the same
  for (HighsInt iCol = 0; iCol < num_col; iCol++) {
    return_status = Highs_passColName(highs, iCol, col_prefix);
    assert(return_status == kHighsStatusOk);
  }
  return_status = Highs_writeModel(highs, "");
  assert(return_status == kHighsStatusError);

  char name[5];  // 3 chars prefix, 1 char iCol, 1 char 0-terminator

  // Define all column names to be different
  for (HighsInt iCol = 0; iCol < num_col; iCol++) {
    sprintf(name, "%s%" HIGHSINT_FORMAT "", col_prefix, iCol);
    return_status = Highs_passColName(highs, iCol, name);
    assert(return_status == kHighsStatusOk);
  }
  return_status = Highs_writeModel(highs, "");
  assert(return_status == kHighsStatusOk);

  // Check that the columns can be found by name
  HighsInt ck_iCol;
  for (HighsInt iCol = 0; iCol < num_col; iCol++) {
    return_status = Highs_getColName(highs, iCol, name);
    assert(return_status == kHighsStatusOk);
    return_status = Highs_getColByName(highs, name, &ck_iCol);
    assert(return_status == kHighsStatusOk);
    assert(ck_iCol == iCol);
  }
  return_status = Highs_getColByName(highs, "FRED", &ck_iCol);
  assert(return_status == kHighsStatusError);

  // Define all row names to be the same
  for (HighsInt iRow = 0; iRow < num_row; iRow++) {
    return_status = Highs_passRowName(highs, iRow, row_prefix);
    assert(return_status == kHighsStatusOk);
  }
  return_status = Highs_writeModel(highs, "");
  assert(return_status == kHighsStatusError);

  // Define all row names to be different
  for (HighsInt iRow = 0; iRow < num_row; iRow++) {
    sprintf(name, "%s%" HIGHSINT_FORMAT, row_prefix, iRow);
    return_status = Highs_passRowName(highs, iRow, name);
    assert(return_status == kHighsStatusOk);
  }
  return_status = Highs_writeModel(highs, "");
  assert(return_status == kHighsStatusOk);

  // Check that the rows can be found by name
  HighsInt ck_iRow;
  for (HighsInt iRow = 0; iRow < num_row; iRow++) {
    char name[5];
    return_status = Highs_getRowName(highs, iRow, name);
    assert(return_status == kHighsStatusOk);
    return_status = Highs_getRowByName(highs, name, &ck_iRow);
    assert(return_status == kHighsStatusOk);
    assert(ck_iRow == iRow);
  }
  return_status = Highs_getRowByName(highs, "FRED", &ck_iRow);
  assert(return_status == kHighsStatusError);

  for (HighsInt iCol = 0; iCol < num_col; iCol++) {
    return_status = Highs_getColName(highs, iCol, name);
    assert(return_status == kHighsStatusOk);
    if (dev_run)
      printf("Column %" HIGHSINT_FORMAT " has name %s\n", iCol, name);
  }

  for (HighsInt iRow = 0; iRow < num_row; iRow++) {
    return_status = Highs_getRowName(highs, iRow, name);
    assert(return_status == kHighsStatusOk);
    if (dev_run)
      printf("Row    %" HIGHSINT_FORMAT " has name %s\n", iRow, name);
  }

  // Check extraction of names for the presolved LP, in which the
  // first row is removed
  Highs_presolve(highs);
  if (dev_run) Highs_writePresolvedModel(highs, "");

  HighsInt presolved_num_col = Highs_getPresolvedNumCol(highs);
  HighsInt presolved_num_row = Highs_getPresolvedNumRow(highs);
  assert(presolved_num_col == num_col);
  assert(presolved_num_row == num_row-1);

  char presolved_name[5];

  return_status = Highs_getPresolvedColName(highs, -1, presolved_name);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getPresolvedRowName(highs, -1, presolved_name);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getPresolvedColName(highs, presolved_num_col, presolved_name);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getPresolvedRowName(highs, presolved_num_row, presolved_name);
  assert(return_status == kHighsStatusError);
  
  for (HighsInt iCol = 0; iCol < presolved_num_col; iCol++) {
    return_status = Highs_getPresolvedColName(highs, iCol, presolved_name);
    assert(return_status == kHighsStatusOk);
    if (dev_run)
      printf("Presolved column %" HIGHSINT_FORMAT " has name %s\n", iCol, presolved_name);
  }

  for (HighsInt iRow = 0; iRow < presolved_num_row; iRow++) {
    return_status = Highs_getPresolvedRowName(highs, iRow, presolved_name);
    assert(return_status == kHighsStatusOk);
    if (dev_run)
      printf("Presolved row    %" HIGHSINT_FORMAT " has name %s\n", iRow, presolved_name);
  }

  Highs_destroy(highs);
}

void fullApiOptions() {
  void* highs;

  highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);

  const double kHighsInf = Highs_getInfinity(highs);
  HighsInt simplex_scale_strategy;
  HighsInt return_status;
  return_status = Highs_getIntOptionValue(highs, "simplex_scale_strategy",
                                          &simplex_scale_strategy);
  assert(return_status == kHighsStatusOk);
  if (dev_run)
    printf("simplex_scale_strategy = %" HIGHSINT_FORMAT ": setting it to 3\n",
           simplex_scale_strategy);
  simplex_scale_strategy = 3;
  return_status = Highs_setIntOptionValue(highs, "simplex_scale_strategy",
                                          simplex_scale_strategy);

  const HighsInt presolve_index = 0;
  char* name = NULL;
  return_status = Highs_getOptionName(highs, presolve_index, &name);
  if (dev_run)
    printf("option %" HIGHSINT_FORMAT " has name %s\n", presolve_index, name);
  const char* presolve = "presolve";
  assert(*name == *presolve);
  free(name);

  HighsInt check_simplex_scale_strategy;
  HighsInt min_simplex_scale_strategy;
  HighsInt max_simplex_scale_strategy;
  HighsInt default_simplex_scale_strategy;
  return_status =
      Highs_getIntOptionValues(highs, "scale_strategy", NULL, NULL, NULL, NULL);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getDoubleOptionValues(highs, "simplex_scale_strategy",
                                              NULL, NULL, NULL, NULL);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getIntOptionValues(
      highs, "simplex_scale_strategy", &check_simplex_scale_strategy,
      &min_simplex_scale_strategy, &max_simplex_scale_strategy,
      &default_simplex_scale_strategy);
  assert(return_status == kHighsStatusOk);
  assert(check_simplex_scale_strategy == simplex_scale_strategy);
  assert(min_simplex_scale_strategy == 0);
  assert(max_simplex_scale_strategy == 4);
  assert(default_simplex_scale_strategy == 2);

  // There are some functions to check what type of option value you should
  // provide.
  HighsInt option_type;
  return_status =
      Highs_getOptionType(highs, "simplex_scale_strategy", &option_type);
  assert(return_status == kHighsStatusOk);
  assert(option_type == kHighsOptionTypeInt);
  return_status = Highs_getOptionType(highs, "bad_option", &option_type);
  assert(return_status == kHighsStatusError);

  double primal_feasibility_tolerance;
  return_status = Highs_getDoubleOptionValue(
      highs, "primal_feasibility_tolerance", &primal_feasibility_tolerance);
  assert(return_status == kHighsStatusOk);
  if (dev_run)
    printf("primal_feasibility_tolerance = %g: setting it to 1e-6\n",
           primal_feasibility_tolerance);
  primal_feasibility_tolerance = 1e-6;
  return_status = Highs_setDoubleOptionValue(
      highs, "primal_feasibility_tolerance", primal_feasibility_tolerance);
  assert(return_status == kHighsStatusOk);

  double check_primal_feasibility_tolerance;
  return_status = Highs_getDoubleOptionValues(
      highs, "primal_feasibility_tolerance",
      &check_primal_feasibility_tolerance, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  assert(check_primal_feasibility_tolerance == primal_feasibility_tolerance);
  double default_primal_feasibility_tolerance;
  double min_primal_feasibility_tolerance;
  double max_primal_feasibility_tolerance;
  return_status = Highs_getDoubleOptionValues(
      highs, "primal_feasibility_tolerance",
      &check_primal_feasibility_tolerance, &min_primal_feasibility_tolerance,
      &max_primal_feasibility_tolerance, &default_primal_feasibility_tolerance);
  assert(min_primal_feasibility_tolerance == 1e-10);
  assert(max_primal_feasibility_tolerance == kHighsInf);
  assert(default_primal_feasibility_tolerance == 1e-7);

  Highs_setStringOptionValue(highs, "presolve", "off");

  return_status = Highs_getStringOptionValues(highs, "pre-solve", NULL, NULL);
  assert(return_status == kHighsStatusError);
  //  char check_presolve_value[kHighsMaximumStringLength];
  char check_presolve_value[512];
  return_status = Highs_getStringOptionValues(highs, "presolve",
                                              check_presolve_value, NULL);
  assert(return_status == kHighsStatusOk);

  // const HighsInt output_flag = 1;
  // return_status = Highs_setBoolOptionValue(highs, "output_flag",
  // output_flag);
  return_status = Highs_setBoolOptionValue(highs, "output_flag", 1);

  assert(return_status == kHighsStatusOk);

  HighsInt check_output_flag, default_output_flag;
  return_status = Highs_getBoolOptionValues(highs, "output_flag", NULL, NULL);
  assert(return_status == kHighsStatusOk);
  return_status =
      Highs_getBoolOptionValues(highs, "output_flag", &check_output_flag, NULL);
  assert(return_status == kHighsStatusOk);
  //    assert( check_output_flag == output_flag );
  assert(check_output_flag == 1);
  return_status = Highs_getBoolOptionValues(
      highs, "output_flag", &check_output_flag, &default_output_flag);
  assert(return_status == kHighsStatusOk);
  //    assert( default_output_flag == output_flag );
  assert(default_output_flag == 1);

  HighsInt num_string_option = 0;
  char* option = NULL;
  HighsInt type;
  HighsInt num_options = Highs_getNumOptions(highs);
  char current_string_value[512];

  if (dev_run) printf("\nString options are:\n");
  for (HighsInt index = 0; index < num_options; index++) {
    Highs_getOptionName(highs, index, &option);
    Highs_getOptionType(highs, option, &type);
    if (type != kHighsOptionTypeString) {
      free(option);
      continue;
    }
    Highs_getStringOptionValues(highs, option, current_string_value, NULL);
    num_string_option++;
    if (dev_run)
      printf("%" HIGHSINT_FORMAT ": %-24s \"%s\"\n", num_string_option, option,
             current_string_value);
    free(option);
  }

  Highs_destroy(highs);
}

void fullApiLp() {
  // Form and solve the LP
  // Min    f  = 2x_0 + 3x_1
  // s.t.                x_1 <= 6
  //       10 <=  x_0 + 2x_1 <= 14
  //        8 <= 2x_0 +  x_1
  // 0 <= x_0 <= 3; 1 <= x_1

  void* highs;

  highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);

  const HighsInt num_col = 2;
  const HighsInt num_row = 3;
  const HighsInt num_nz = 5;

  // Define the column costs, lower bounds and upper bounds
  double col_cost[2] = {2.0, 3.0};
  double col_lower[2] = {0.0, 1.0};
  double col_upper[2] = {3.0, 1.0e30};
  // Define the row lower bounds and upper bounds
  double row_lower[3] = {-1.0e30, 10.0, 8.0};
  double row_upper[3] = {6.0, 14.0, 1.0e30};
  // Define the constraint matrix row-wise, as it is added to the LP
  // with the rows
  HighsInt arstart[3] = {0, 1, 3};
  HighsInt arindex[5] = {1, 0, 1, 0, 1};
  double arvalue[5] = {1.0, 1.0, 2.0, 2.0, 1.0};

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  double* col_dual = (double*)malloc(sizeof(double) * num_col);
  double* row_value = (double*)malloc(sizeof(double) * num_row);
  double* row_dual = (double*)malloc(sizeof(double) * num_row);

  HighsInt* col_basis_status = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* row_basis_status = (HighsInt*)malloc(sizeof(HighsInt) * num_row);

  // Add two columns to the empty LP
  assert(Highs_addCols(highs, num_col, col_cost, col_lower, col_upper, 0, NULL,
                       NULL, NULL) == 0);
  // Add three rows to the 2-column LP
  assert(Highs_addRows(highs, num_row, row_lower, row_upper, num_nz, arstart,
                       arindex, arvalue) == 0);

  HighsInt sense;
  HighsInt return_status;
  return_status = Highs_getObjectiveSense(highs, &sense);
  assert(return_status == kHighsStatusOk);
  if (dev_run)
    printf("LP problem has objective sense = %" HIGHSINT_FORMAT "\n", sense);
  assert(sense == kHighsObjSenseMinimize);

  sense *= -1;
  return_status = Highs_changeObjectiveSense(highs, sense);
  assert(return_status == kHighsStatusOk);
  assert(sense == kHighsObjSenseMaximize);

  sense *= -1;
  return_status = Highs_changeObjectiveSense(highs, sense);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_getObjectiveSense(highs, &sense);
  assert(return_status == kHighsStatusOk);
  if (dev_run)
    printf("LP problem has old objective sense = %" HIGHSINT_FORMAT "\n",
           sense);
  assert(sense == kHighsObjSenseMinimize);

  // fetch column data (just first column)
  {
    const HighsInt get_col = 0;
    const HighsInt num_get_col = 1;
    HighsInt get_num_col = 0;
    double* get_costs = (double*)malloc(sizeof(double) * num_get_col);
    double* get_lower = (double*)malloc(sizeof(double) * num_get_col);
    double* get_upper = (double*)malloc(sizeof(double) * num_get_col);
    HighsInt get_num_nz = 0;

    return_status = Highs_getColsByRange(highs, get_col, get_col, &get_num_col,
                                         get_costs, get_lower, get_upper,
                                         &get_num_nz, NULL, NULL, NULL);
    assert(return_status == kHighsStatusOk);

    assertIntValuesEqual("getCols get_num_col", get_num_col, num_get_col);
    assertDoubleValuesEqual("getCols get_costs", get_costs[0],
                            col_cost[get_col]);
    assertDoubleValuesEqual("getCols get_lower", get_lower[0],
                            col_lower[get_col]);
    assertDoubleValuesEqual("getCols get_upper", get_upper[0],
                            col_upper[get_col]);
    assertIntValuesEqual("getCols get_num_nz", get_num_nz, 2);

    // could also check coefficients by calling again...

    free(get_upper);
    free(get_lower);
    free(get_costs);
  }

  // fetch row data (just 2nd row: 10 <=  x_0 + 2x_1 <= 14)
  {
    const HighsInt get_row = 1;
    const HighsInt num_get_row = 1;
    HighsInt get_num_row = 0;
    double* get_lower = (double*)malloc(sizeof(double) * num_get_row);
    double* get_upper = (double*)malloc(sizeof(double) * num_get_row);
    HighsInt get_num_nz = 0;

    assertIntValuesEqual("getNumRows", Highs_getNumRows(highs), num_row);

    return_status =
        Highs_getRowsByRange(highs, get_row, get_row, &get_num_row, get_lower,
                             get_upper, &get_num_nz, NULL, NULL, NULL);
    assert(return_status == kHighsStatusOk);

    assertIntValuesEqual("getRows get_num_row", get_num_row, num_get_row);
    assertDoubleValuesEqual("getRows get_lower", get_lower[0],
                            row_lower[get_row]);
    assertDoubleValuesEqual("getRows get_upper", get_upper[0],
                            row_upper[get_row]);
    assertIntValuesEqual("getRows get_num_nz", get_num_nz, 2);

    // could also check coefficients by calling again...

    free(get_upper);
    free(get_lower);
  }

  return_status = Highs_setBoolOptionValue(highs, "output_flag", 0);
  assert(return_status == kHighsStatusOk);
  if (dev_run) printf("Running quietly...\n");
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  if (dev_run) printf("Running loudly...\n");

  // Get the model status
  HighsInt model_status = Highs_getModelStatus(highs);

  if (dev_run)
    printf("Run status = %" HIGHSINT_FORMAT "; Model status = %" HIGHSINT_FORMAT
           "\n",
           return_status, model_status);

  double objective_function_value;
  return_status = Highs_getDoubleInfoValue(highs, "objective_function_value",
                                           &objective_function_value);
  assert(return_status == kHighsStatusOk);
  HighsInt simplex_iteration_count;
  return_status = Highs_getIntInfoValue(highs, "simplex_iteration_count",
                                        &simplex_iteration_count);
  assert(return_status == kHighsStatusOk);
  HighsInt primal_solution_status;
  return_status = Highs_getIntInfoValue(highs, "primal_solution_status",
                                        &primal_solution_status);
  assert(return_status == kHighsStatusOk);
  HighsInt dual_solution_status;
  return_status = Highs_getIntInfoValue(highs, "dual_solution_status",
                                        &dual_solution_status);
  assert(return_status == kHighsStatusOk);

  if (dev_run) {
    printf("Objective value = %g; Iteration count = %" HIGHSINT_FORMAT "\n",
           objective_function_value, simplex_iteration_count);
    if (model_status == kHighsModelStatusOptimal) {
      // Get the primal and dual solution
      return_status =
          Highs_getSolution(highs, col_value, col_dual, row_value, row_dual);
      assert(return_status == kHighsStatusOk);
      // Get the basis
      return_status = Highs_getBasis(highs, col_basis_status, row_basis_status);
      assert(return_status == kHighsStatusOk);
      // Report the column primal and dual values, and basis status
      for (HighsInt iCol = 0; iCol < num_col; iCol++)
        printf("Col%" HIGHSINT_FORMAT
               " = %lf; dual = %lf; status = %" HIGHSINT_FORMAT "; \n",
               iCol, col_value[iCol], col_dual[iCol], col_basis_status[iCol]);
      // Report the row primal and dual values, and basis status
      for (HighsInt iRow = 0; iRow < num_row; iRow++)
        printf("Row%" HIGHSINT_FORMAT
               " = %lf; dual = %lf; status = %" HIGHSINT_FORMAT "; \n",
               iRow, row_value[iRow], row_dual[iRow], row_basis_status[iRow]);
    }
  }
  free(col_value);
  free(col_dual);
  free(row_value);
  free(row_dual);
  free(col_basis_status);
  free(row_basis_status);

  Highs_destroy(highs);

  // Define the constraint matrix to pass to the LP
  HighsInt a_format = kHighsMatrixFormatColwise;
  sense = kHighsObjSenseMinimize;
  double offset = 0;
  HighsInt a_start[2] = {0, 2};
  HighsInt a_index[5] = {1, 2, 0, 1, 2};
  double a_value[5] = {1.0, 2.0, 1.0, 2.0, 1.0};
  highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);
  return_status = Highs_passLp(highs, num_col, num_row, num_nz, a_format, sense,
                               offset, col_cost, col_lower, col_upper,
                               row_lower, row_upper, a_start, a_index, a_value);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  model_status = Highs_getModelStatus(highs);
  assert(model_status == kHighsModelStatusOptimal);
  if (dev_run)
    printf("Run status = %" HIGHSINT_FORMAT "; Model status = %" HIGHSINT_FORMAT
           "\n",
           return_status, model_status);

  Highs_destroy(highs);
}

void fullApiMip() {
  // The use of the full HiGHS API is illustrated for the MIP
  //
  // Min    f  = -3x_0 - 2x_1 - x_2
  // s.t.          x_0 +  x_1 + x_2 <=  7
  //              4x_0 + 2x_1 + x_2  = 12
  //              x_0 >=0; x_1 >= 0; x_2 binary

  const HighsInt num_col = 3;
  const HighsInt num_row = 2;
  const HighsInt num_nz = 6;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;

  // Define the column costs, lower bounds and upper bounds
  double col_cost[3] = {-3.0, -2.0, -1.0};
  double col_lower[3] = {0.0, 0.0, 0.0};
  double col_upper[3] = {1.0e30, 1.0e30, 1.0};
  // Define the row lower bounds and upper bounds
  double row_lower[2] = {-1.0e30, 12.0};
  double row_upper[2] = {7.0, 12.0};
  // Define the constraint matrix column-wise
  HighsInt a_start[3] = {0, 2, 4};
  HighsInt a_index[6] = {0, 1, 0, 1, 0, 1};
  double a_value[6] = {1.0, 4.0, 1.0, 2.0, 1.0, 1.0};

  HighsInt integrality[3] = {kHighsVarTypeInteger, kHighsVarTypeInteger,
                             kHighsVarTypeInteger};

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  double* row_value = (double*)malloc(sizeof(double) * num_row);

  HighsInt return_status;

  void* highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);
  return_status =
      Highs_passMip(highs, num_col, num_row, num_nz, a_format, sense, offset,
                    col_cost, col_lower, col_upper, row_lower, row_upper,
                    a_start, a_index, a_value, integrality);
  assert(return_status == kHighsStatusOk);
  Highs_setStringOptionValue(highs, "presolve", "off");
  return_status = Highs_run(highs);
  // mip_node_count is always int64_t, so the following should be an
  // error depending on whether HIGHSINT64 is set
  HighsInt mip_node_count_int;
  HighsInt required_return_status = kHighsStatusError;
#ifdef HIGHSINT64
  required_return_status = kHighsStatusOk;
#endif
  return_status =
      Highs_getIntInfoValue(highs, "mip_node_count", &mip_node_count_int);
  assert(return_status == required_return_status);
  int64_t mip_node_count;
  return_status =
      Highs_getInt64InfoValue(highs, "mip_node_count", &mip_node_count);
  assert(return_status == kHighsStatusOk);
  assert(mip_node_count == 1);

  // Test Highs_getColIntegrality
  HighsInt col_integrality;
  return_status = Highs_getColIntegrality(highs, -1, &col_integrality);
  assert(return_status == kHighsStatusError);
  return_status = Highs_getColIntegrality(highs, num_col, &col_integrality);
  assert(return_status == kHighsStatusError);
  for (HighsInt iCol = 0; iCol < num_col; iCol++) {
    return_status = Highs_getColIntegrality(highs, iCol, &col_integrality);
    assert(return_status == kHighsStatusOk);
    assert(col_integrality == 1);
  }

  Highs_destroy(highs);

  free(col_value);
  free(row_value);
}

void fullApiQp() {
  double required_objective_function_value;
  double required_x0;
  double required_x1;
  double objective_function_value;
  HighsInt model_status;
  HighsInt return_status;
  void* highs = Highs_create();
  const double inf = Highs_getInfinity(highs);
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);

  // Oscar's edge case
  //
  // min x^2 + x = x(x + 1)

  HighsInt num_col = 0;
  return_status = Highs_addCol(highs, 1.0, -inf, inf, 0, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  num_col++;

  double offset = 0.25;
  return_status = Highs_changeObjectiveOffset(highs, offset);
  assert(return_status == kHighsStatusOk);

  HighsInt q_dim = 1;
  HighsInt q_num_nz = 1;
  HighsInt q_format = kHighsHessianFormatTriangular;
  HighsInt* q_start = (HighsInt*)malloc(sizeof(HighsInt) * q_dim);
  HighsInt* q_index = (HighsInt*)malloc(sizeof(HighsInt) * q_num_nz);
  double* q_value = (double*)malloc(sizeof(double) * q_num_nz);
  q_start[0] = 0;
  q_index[0] = 0;
  q_value[0] = 2.0;
  return_status = Highs_passHessian(highs, q_dim, q_num_nz, q_format, q_start,
                                    q_index, q_value);
  assert(return_status == kHighsStatusOk);
  if (dev_run) Highs_writeModel(highs, "");
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  model_status = Highs_getModelStatus(highs);
  assertIntValuesEqual("Model status for 1-d QP", model_status,
                       kHighsModelStatusOptimal);

  required_objective_function_value = 0;
  required_x0 = -0.5;
  objective_function_value = Highs_getObjectiveValue(highs);
  assertDoubleValuesEqual("Objective", objective_function_value,
                          required_objective_function_value);

  double* col_solution = (double*)malloc(sizeof(double) * num_col);

  return_status = Highs_getSolution(highs, col_solution, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  assertDoubleValuesEqual("x0", col_solution[0], required_x0);

  if (dev_run) Highs_writeSolutionPretty(highs, "");
  // Add a variable x1 with objective x1^2 - x1
  //
  // Add the variable
  return_status = Highs_addCol(highs, -1.0, -inf, inf, 0, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  num_col++;
  // Can solve the model before the Hessian has been replaced
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  assertIntValuesEqual("Run status for 2-d QP with OK Hessian", return_status,
                       0);

  model_status = Highs_getModelStatus(highs);
  assertIntValuesEqual("Model status for this 2-d QP with OK Hessian",
                       model_status, kHighsModelStatusUnbounded);

  free(q_start);
  free(q_index);
  free(q_value);

  // Pass the new Hessian
  q_dim = 2;
  q_num_nz = 2;
  q_start = (HighsInt*)malloc(sizeof(HighsInt) * q_dim);
  q_index = (HighsInt*)malloc(sizeof(HighsInt) * q_num_nz);
  q_value = (double*)malloc(sizeof(double) * q_num_nz);
  q_start[0] = 0;
  q_index[0] = 0;
  q_value[0] = 2.0;
  q_start[1] = 1;
  q_index[1] = 1;
  q_value[1] = 2.0;
  return_status = Highs_passHessian(highs, q_dim, q_num_nz, q_format, q_start,
                                    q_index, q_value);
  assert(return_status == kHighsStatusOk);
  if (dev_run) Highs_writeModel(highs, "");

  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);

  model_status = Highs_getModelStatus(highs);
  assertIntValuesEqual("Model status for 2-d QP", model_status,
                       kHighsModelStatusOptimal);

  required_objective_function_value = -0.25;
  required_x1 = 0.5;
  objective_function_value = Highs_getObjectiveValue(highs);
  assertDoubleValuesEqual("Objective", objective_function_value,
                          required_objective_function_value);

  free(col_solution);
  col_solution = (double*)malloc(sizeof(double) * num_col);

  return_status = Highs_getSolution(highs, col_solution, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  assertDoubleValuesEqual("x0", col_solution[0], required_x0);
  assertDoubleValuesEqual("x1", col_solution[1], required_x1);

  // Illustrate methods for getting and changing the offset by getting
  // the current offset, shifting it by the current objective and
  // checking that the objective value is changed accordingly

  double check_offset;
  return_status = Highs_getObjectiveOffset(highs, &check_offset);
  assert(return_status == kHighsStatusOk);
  assertDoubleValuesEqual("Offset", check_offset, offset);

  double dl_offset = -objective_function_value;
  offset += dl_offset;

  return_status = Highs_changeObjectiveOffset(highs, offset);
  assert(return_status == kHighsStatusOk);
  required_objective_function_value += dl_offset;
  objective_function_value = Highs_getObjectiveValue(highs);
  assertDoubleValuesEqual("Objective with new offset", objective_function_value,
                          required_objective_function_value);

  // Add the constraint 0.5 <= x0 + x1
  HighsInt a_index[2] = {0, 1};
  double a_value[2] = {1, 1};
  return_status = Highs_addRow(highs, 0.5, inf, 2, a_index, a_value);
  assert(return_status == kHighsStatusOk);
  if (dev_run) Highs_writeModel(highs, "");

  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  assertIntValuesEqual("Run status for 2-d QP with constraint", return_status,
                       kHighsStatusOk);

  model_status = Highs_getModelStatus(highs);
  assertIntValuesEqual("Model status for 2-d QP with constraint", model_status,
                       kHighsModelStatusOptimal);

  required_objective_function_value = 0.125;
  required_x0 = -0.25;
  required_x1 = 0.75;

  objective_function_value = Highs_getObjectiveValue(highs);
  assertDoubleValuesEqual("Objective", objective_function_value,
                          required_objective_function_value);

  return_status = Highs_getSolution(highs, col_solution, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  assertDoubleValuesEqual("x0", col_solution[0], required_x0);
  assertDoubleValuesEqual("x1", col_solution[1], required_x1);

  // Add bounds to make the QP infeasible
  return_status = Highs_changeColBounds(highs, 0, -inf, 0);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_changeColBounds(highs, 1, -inf, 0);
  assert(return_status == kHighsStatusOk);

  if (dev_run) Highs_writeModel(highs, "");

  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  assertIntValuesEqual("Run status for infeasible 2-d QP", return_status, 0);

  model_status = Highs_getModelStatus(highs);
  assertIntValuesEqual("Model status for infeasible 2-d QP", model_status, 8);
  assert(model_status == kHighsModelStatusInfeasible);

  Highs_destroy(highs);

  free(q_start);
  free(q_index);
  free(q_value);
  free(col_solution);
}

void passPresolveGetLp() {
  // Form and solve the LP
  // Min    f  = 2x_0 + 3x_1
  // s.t.                x_1 <= 6
  //       10 <=  x_0 + 2x_1 <= 14
  //        8 <= 2x_0 +  x_1
  // 0 <= x_0 <= 3; 1 <= x_1

  void* highs;

  highs = Highs_create();
  const double kHighsInf = Highs_getInfinity(highs);
  HighsInt model_status;
  HighsInt return_status;

  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;
  // Define the column costs, lower bounds and upper bounds

  const HighsInt num_col = 2;
  const HighsInt num_row = 3;
  const HighsInt num_nz = 5;

  double col_cost[2] = {2.0, 3.0};
  double col_lower[2] = {0.0, 1.0};
  double col_upper[2] = {3.0, kHighsInf};
  // Define the row lower bounds and upper bounds
  double row_lower[3] = {-kHighsInf, 10.0, 8.0};
  double row_upper[3] = {6.0, 14.0, kHighsInf};
  HighsInt a_start[2] = {0, 2};
  HighsInt a_index[5] = {1, 2, 0, 1, 2};
  double a_value[5] = {1.0, 2.0, 1.0, 2.0, 1.0};

  return_status = Highs_passLp(highs, num_col, num_row, num_nz, a_format, sense,
                               offset, col_cost, col_lower, col_upper,
                               row_lower, row_upper, a_start, a_index, a_value);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_presolve(highs);
  assert(return_status == kHighsStatusOk);
  for (HighsInt k = 0; k < 2; k++) {
    // Loop twice: once for col-wise; once for row-wise
    HighsInt presolved_num_col = Highs_getPresolvedNumCol(highs);
    HighsInt presolved_num_row = Highs_getPresolvedNumRow(highs);
    HighsInt presolved_num_nz = Highs_getPresolvedNumNz(highs);
    HighsInt presolved_a_format =
        k == 0 ? kHighsMatrixFormatColwise : kHighsMatrixFormatRowwise;
    HighsInt presolved_sense;
    double presolved_offset;
    double* presolved_col_cost =
        (double*)malloc(sizeof(double) * presolved_num_col);
    double* presolved_col_lower =
        (double*)malloc(sizeof(double) * presolved_num_col);
    double* presolved_col_upper =
        (double*)malloc(sizeof(double) * presolved_num_col);
    double* presolved_row_lower =
        (double*)malloc(sizeof(double) * presolved_num_row);
    double* presolved_row_upper =
        (double*)malloc(sizeof(double) * presolved_num_row);
    HighsInt* presolved_a_start =
        (HighsInt*)malloc(sizeof(HighsInt) * (presolved_num_col + 1));
    HighsInt* presolved_a_index =
        (HighsInt*)malloc(sizeof(HighsInt) * presolved_num_nz);
    double* presolved_a_value =
        (double*)malloc(sizeof(double) * presolved_num_nz);

    return_status = Highs_getPresolvedLp(
        highs, presolved_a_format, &presolved_num_col, &presolved_num_row,
        &presolved_num_nz, &presolved_sense, &presolved_offset,
        presolved_col_cost, presolved_col_lower, presolved_col_upper,
        presolved_row_lower, presolved_row_upper, presolved_a_start,
        presolved_a_index, presolved_a_value, NULL);
    assert(return_status == kHighsStatusOk);
    // Solve the presolved LP within a local version of HiGHS
    void* local_highs;
    local_highs = Highs_create();
    Highs_setBoolOptionValue(local_highs, "output_flag", dev_run);
    Highs_setStringOptionValue(local_highs, "presolve", "off");
    return_status = Highs_passLp(
        local_highs, presolved_num_col, presolved_num_row, presolved_num_nz,
        presolved_a_format, presolved_sense, presolved_offset,
        presolved_col_cost, presolved_col_lower, presolved_col_upper,
        presolved_row_lower, presolved_row_upper, presolved_a_start,
        presolved_a_index, presolved_a_value);
    assert(return_status == kHighsStatusOk);
    return_status = Highs_run(local_highs);

    double* col_value = (double*)malloc(sizeof(double) * num_col);
    double* col_dual = (double*)malloc(sizeof(double) * num_col);
    double* row_dual = (double*)malloc(sizeof(double) * num_row);

    return_status =
        Highs_getSolution(local_highs, col_value, col_dual, NULL, row_dual);
    assert(return_status == kHighsStatusOk);

    return_status = Highs_postsolve(highs, col_value, col_dual, row_dual);
    assert(return_status == kHighsStatusOk);

    model_status = Highs_getModelStatus(highs);
    assert(model_status == kHighsModelStatusOptimal);

    // With just the primal solution, optimality cannot be determined

    return_status = Highs_postsolve(highs, col_value, NULL, NULL);
    assert(return_status == kHighsStatusWarning);

    model_status = Highs_getModelStatus(highs);
    assert(model_status == kHighsModelStatusUnknown);

    free(presolved_col_cost);
    free(presolved_col_lower);
    free(presolved_col_upper);
    free(presolved_row_lower);
    free(presolved_row_upper);
    free(presolved_a_start);
    free(presolved_a_index);
    free(presolved_a_value);
    free(col_value);
    free(col_dual);
    free(row_dual);
  }
}

void options() {
  void* highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);

  HighsInt simplex_scale_strategy;
  HighsInt return_status;
  return_status = Highs_setIntOptionValue(highs, "simplex_scale_strategy", 0);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_getIntOptionValue(highs, "simplex_scale_strategy",
                                          &simplex_scale_strategy);
  assert(return_status == kHighsStatusOk);
  assert(simplex_scale_strategy == 0);

  double primal_feasibility_tolerance;
  return_status =
      Highs_setDoubleOptionValue(highs, "primal_feasibility_tolerance", 2.0);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_getDoubleOptionValue(
      highs, "primal_feasibility_tolerance", &primal_feasibility_tolerance);
  assert(return_status == kHighsStatusOk);
  assert(primal_feasibility_tolerance == 2.0);

  Highs_destroy(highs);
}

void testGetColsByRange() {
  void* highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);
  HighsInt return_status;
  return_status = Highs_addCol(highs, -1.0, 0.0, 1.0, 0, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_addCol(highs, -1.0, 0.0, 1.0, 0, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  HighsInt a_index[2] = {0, 1};
  double a_value[2] = {1.0, -1.0};
  return_status = Highs_addRow(highs, 0.0, 0.0, 2, a_index, a_value);
  assert(return_status == kHighsStatusOk);
  HighsInt num_cols;
  HighsInt num_nz;
  HighsInt matrix_start[2] = {-1, -1};
  return_status = Highs_getColsByRange(highs, 0, 1, &num_cols, NULL, NULL, NULL,
                                       &num_nz, matrix_start, NULL, NULL);
  assert(return_status == kHighsStatusOk);
  assert(num_cols == 2);
  assert(num_nz == 2);
  assert(matrix_start[0] == 0);
  assert(matrix_start[1] == 1);
  HighsInt matrix_index[2] = {-1, -1};
  double matrix_value[2] = {0.0, 0.0};
  return_status =
      Highs_getColsByRange(highs, 0, 1, &num_cols, NULL, NULL, NULL, &num_nz,
                           matrix_start, matrix_index, matrix_value);
  assert(return_status == kHighsStatusOk);
  assert(matrix_index[0] == 0);
  assert(matrix_index[1] == 0);
  assert(matrix_value[0] == 1.0);
  assert(matrix_value[1] == -1.0);

  Highs_destroy(highs);
}

void testPassHessian() {
  void* highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);
  Highs_addCol(highs, 2.0, 0.0, 2.0, 0, NULL, NULL);
  Highs_changeObjectiveSense(highs, kHighsObjSenseMaximize);
  HighsInt start[1] = {0};
  HighsInt index[1] = {0};
  double value[1] = {-2.0};
  HighsInt return_status;
  return_status = Highs_passHessian(highs, 1, 1, 1, start, index, value);
  assertIntValuesEqual("Return of passHessian", return_status, kHighsStatusOk);
  Highs_run(highs);
  // Solving max -x^2 + 2x
  const double optimal_objective_value = 1;
  const double primal = 1;
  const double dual = 0;
  assertIntValuesEqual("Status", Highs_getModelStatus(highs),
                       kHighsModelStatusOptimal);  // kOptimal
  double col_value[1] = {-123.0};
  double col_dual[1] = {0.0};
  Highs_getSolution(highs, col_value, col_dual, NULL, NULL);
  double objective_value = Highs_getObjectiveValue(highs);
  assertDoubleValuesEqual("Objective", objective_value,
                          optimal_objective_value);
  assertDoubleValuesEqual("Primal", col_value[0], primal);
  assertDoubleValuesEqual("Dual", col_dual[0], dual);

  Highs_destroy(highs);
}

void testRanging() {
  void* highs = Highs_create();
  if (!dev_run) Highs_setBoolOptionValue(highs, "output_flag", 0);
  //
  // Set up
  //        min y
  //        s.t.
  //        -x + y >= 2
  //        x + y >= 0
  //
  double inf = Highs_getInfinity(highs);
  Highs_addVar(highs, -inf, inf);
  Highs_addVar(highs, -inf, inf);
  Highs_changeColCost(highs, 0, 0);
  Highs_changeColCost(highs, 1, 1);
  HighsInt index[2] = {0.0, 1.0};
  double value[2] = {-1, 1};
  Highs_addRow(highs, 2, inf, 2, index, value);
  value[0] = 1.0;
  Highs_addRow(highs, 0, inf, 2, index, value);
  // Cost ranging
  // c0 2 -1 1 0
  // c1 0 0 inf inf
  //
  // Bound ranging
  // Columns
  // c0 1 -inf inf 1
  // c1 1 1 inf 1
  // Rows
  // r0 -inf -inf inf inf
  // r1 -inf -inf inf inf
  Highs_run(highs);
  HighsInt num_col = Highs_getNumCol(highs);
  HighsInt num_row = Highs_getNumRow(highs);
  double* col_cost_up_value = (double*)malloc(sizeof(double) * num_col);
  double* col_cost_up_objective = (double*)malloc(sizeof(double) * num_col);
  HighsInt* col_cost_up_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* col_cost_up_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  double* col_cost_dn_value = (double*)malloc(sizeof(double) * num_col);
  double* col_cost_dn_objective = (double*)malloc(sizeof(double) * num_col);
  HighsInt* col_cost_dn_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* col_cost_dn_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  double* col_bound_up_value = (double*)malloc(sizeof(double) * num_col);
  double* col_bound_up_objective = (double*)malloc(sizeof(double) * num_col);
  HighsInt* col_bound_up_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* col_bound_up_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  double* col_bound_dn_value = (double*)malloc(sizeof(double) * num_col);
  double* col_bound_dn_objective = (double*)malloc(sizeof(double) * num_col);
  HighsInt* col_bound_dn_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* col_bound_dn_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  double* row_bound_up_value = (double*)malloc(sizeof(double) * num_row);
  double* row_bound_up_objective = (double*)malloc(sizeof(double) * num_row);
  HighsInt* row_bound_up_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_row);
  HighsInt* row_bound_up_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_row);
  double* row_bound_dn_value = (double*)malloc(sizeof(double) * num_row);
  double* row_bound_dn_objective = (double*)malloc(sizeof(double) * num_row);
  HighsInt* row_bound_dn_in_var = (HighsInt*)malloc(sizeof(HighsInt) * num_row);
  HighsInt* row_bound_dn_ou_var = (HighsInt*)malloc(sizeof(HighsInt) * num_row);
  HighsInt status = Highs_getRanging(
      highs,
      //
      col_cost_up_value, col_cost_up_objective, col_cost_up_in_var,
      col_cost_up_ou_var, col_cost_dn_value, col_cost_dn_objective,
      col_cost_dn_in_var, col_cost_dn_ou_var, col_bound_up_value,
      col_bound_up_objective, col_bound_up_in_var, col_bound_up_ou_var,
      col_bound_dn_value, col_bound_dn_objective, col_bound_dn_in_var,
      col_bound_dn_ou_var, row_bound_up_value, row_bound_up_objective,
      row_bound_up_in_var, row_bound_up_ou_var, row_bound_dn_value,
      row_bound_dn_objective, row_bound_dn_in_var, row_bound_dn_ou_var);
  assert(status == kHighsStatusOk);

  assertDoubleValuesEqual("col_cost_dn_objective[0]", col_cost_dn_objective[0],
                          2);
  assertDoubleValuesEqual("col_cost_dn_value[0]", col_cost_dn_value[0], -1);
  assertDoubleValuesEqual("col_cost_up_value[0]", col_cost_up_value[0], 1);
  assertDoubleValuesEqual("col_cost_up_objective[0]", col_cost_up_objective[0],
                          0);
  assertDoubleValuesEqual("col_cost_dn_objective[1]", col_cost_dn_objective[1],
                          0);
  assertDoubleValuesEqual("col_cost_dn_value[1]", col_cost_dn_value[1], 0);
  assertDoubleValuesEqual("col_cost_up_value[1]", col_cost_up_value[1], inf);
  assertDoubleValuesEqual("col_cost_up_objective[1]", col_cost_up_objective[1],
                          inf);

  assertDoubleValuesEqual("col_bound_dn_objective[0]",
                          col_bound_dn_objective[0], 1);
  assertDoubleValuesEqual("col_bound_dn_value[0]", col_bound_dn_value[0], -inf);
  assertDoubleValuesEqual("col_bound_up_value[0]", col_bound_up_value[0], inf);
  assertDoubleValuesEqual("col_bound_up_objective[0]",
                          col_bound_up_objective[0], 1);
  assertDoubleValuesEqual("col_bound_dn_objective[1]",
                          col_bound_dn_objective[1], 1);
  assertDoubleValuesEqual("col_bound_dn_value[1]", col_bound_dn_value[1], 1);
  assertDoubleValuesEqual("col_bound_up_value[1]", col_bound_up_value[1], inf);
  assertDoubleValuesEqual("col_bound_up_objective[1]",
                          col_bound_up_objective[1], 1);

  assertDoubleValuesEqual("row_bound_dn_objective[0]",
                          row_bound_dn_objective[0], -inf);
  assertDoubleValuesEqual("row_bound_dn_value[0]", row_bound_dn_value[0], -inf);
  assertDoubleValuesEqual("row_bound_up_value[0]", row_bound_up_value[0], inf);
  assertDoubleValuesEqual("row_bound_up_objective[0]",
                          row_bound_up_objective[0], inf);
  assertDoubleValuesEqual("row_bound_dn_objective[1]",
                          row_bound_dn_objective[1], -inf);
  assertDoubleValuesEqual("row_bound_dn_value[1]", row_bound_dn_value[1], -inf);
  assertDoubleValuesEqual("row_bound_up_value[1]", row_bound_up_value[1], inf);
  assertDoubleValuesEqual("row_bound_up_objective[1]",
                          row_bound_up_objective[1], inf);

  free(col_cost_up_value);
  free(col_cost_up_objective);
  free(col_cost_up_in_var);
  free(col_cost_up_ou_var);
  free(col_cost_dn_value);
  free(col_cost_dn_objective);
  free(col_cost_dn_in_var);
  free(col_cost_dn_ou_var);
  free(col_bound_up_value);
  free(col_bound_up_objective);
  free(col_bound_up_in_var);
  free(col_bound_up_ou_var);
  free(col_bound_dn_value);
  free(col_bound_dn_objective);
  free(col_bound_dn_in_var);
  free(col_bound_dn_ou_var);
  free(row_bound_up_value);
  free(row_bound_up_objective);
  free(row_bound_up_in_var);
  free(row_bound_up_ou_var);
  free(row_bound_dn_value);
  free(row_bound_dn_objective);
  free(row_bound_dn_in_var);
  free(row_bound_dn_ou_var);

  Highs_destroy(highs);
}

void testFeasibilityRelaxation() {
  void* highs;
  highs = Highs_create();
  const double kHighsInf = Highs_getInfinity(highs);
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt return_status;

  HighsInt num_col = 2;
  HighsInt num_row = 3;
  HighsInt num_nz = 6;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;
  double col_cost[2] = {1, -2};
  double col_lower[2] = {5, -kHighsInf};
  double col_upper[2] = {kHighsInf, kHighsInf};
  double row_lower[3] = {2, -kHighsInf, -kHighsInf};
  double row_upper[3] = {kHighsInf, 1, 20};
  HighsInt a_start[2] = {0, 3};
  HighsInt a_index[6] = {0, 1, 2, 0, 1, 2};
  double a_value[6] = {-1, -3, 20, 21, 2, 1};
  HighsInt integrality[2] = {kHighsVarTypeInteger, kHighsVarTypeInteger};

  Highs_passMip(highs, num_col, num_row, num_nz, a_format, sense, offset,
                col_cost, col_lower, col_upper, row_lower, row_upper, a_start,
                a_index, a_value, integrality);
  Highs_feasibilityRelaxation(highs, 1, 1, 1, NULL, NULL, NULL);
  double objective_function_value;
  Highs_getDoubleInfoValue(highs, "objective_function_value",
                           &objective_function_value);
  double* col_value = (double*)malloc(sizeof(double) * num_col);
  double* col_dual = (double*)malloc(sizeof(double) * num_col);
  double* row_value = (double*)malloc(sizeof(double) * num_row);
  double* row_dual = (double*)malloc(sizeof(double) * num_row);
  return_status =
      Highs_getSolution(highs, col_value, col_dual, row_value, row_dual);
  assert(return_status == kHighsStatusOk);
  assertDoubleValuesEqual("objective_function_value", objective_function_value,
                          5);
  assertDoubleValuesEqual("solution_value[0]", col_value[0], 1);
  assertDoubleValuesEqual("solution_value[1]", col_value[1], 1);

  free(col_value);
  free(col_dual);
  free(row_value);
  free(row_dual);

  Highs_destroy(highs);
}

void testCallback() {
  HighsInt num_col = 7;
  HighsInt num_row = 1;
  HighsInt num_nz = num_col;
  HighsInt a_format = kHighsMatrixFormatRowwise;
  HighsInt sense = kHighsObjSenseMaximize;
  double offset = 0;
  double col_cost[7] = {8, 1, 7, 2, 1, 2, 1};
  double col_lower[7] = {0, 0, 0, 0, 0, 0, 0};
  double col_upper[7] = {1, 1, 1, 1, 1, 1, 1};
  double row_lower[1] = {0};
  double row_upper[1] = {28};
  HighsInt a_start[2] = {0, 7};
  HighsInt a_index[7] = {0, 1, 2, 3, 4, 5, 6};
  double a_value[7] = {9, 6, 7, 9, 7, 9, 9};
  HighsInt integrality[7] = {kHighsVarTypeInteger, kHighsVarTypeInteger,
                             kHighsVarTypeInteger, kHighsVarTypeInteger,
                             kHighsVarTypeInteger, kHighsVarTypeInteger,
                             kHighsVarTypeInteger};

  void* highs;
  highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  Highs_passMip(highs, num_col, num_row, num_nz, a_format, sense, offset,
                col_cost, col_lower, col_upper, row_lower, row_upper, a_start,
                a_index, a_value, integrality);

  Highs_setCallback(highs, userCallback, NULL);
  Highs_startCallback(highs, kHighsCallbackLogging);
  Highs_startCallback(highs, kHighsCallbackMipInterrupt);
  Highs_run(highs);
  double objective_function_value;
  Highs_getDoubleInfoValue(highs, "objective_function_value",
                           &objective_function_value);
  double inf = Highs_getInfinity(highs);
  assertDoubleValuesEqual("objective_function_value", objective_function_value,
                          inf);
  Highs_stopCallback(highs, kHighsCallbackMipInterrupt);
  Highs_run(highs);
  Highs_getDoubleInfoValue(highs, "objective_function_value",
                           &objective_function_value);
  assertDoubleValuesEqual("objective_function_value", objective_function_value,
                          17);

  double user_callback_data = inf;
  void* p_user_callback_data = (void*)(&user_callback_data);

  Highs_setCallback(highs, userCallback, p_user_callback_data);
  Highs_clearSolver(highs);
  Highs_startCallback(highs, kHighsCallbackMipImprovingSolution);
  Highs_run(highs);

  Highs_destroy(highs);
}

void testGetModel() {
  void* highs;
  highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  const double inf = Highs_getInfinity(highs);

  HighsInt num_col = 2;
  HighsInt num_row = 2;
  HighsInt num_nz = 4;
  HighsInt sense = -1;
  double col_cost[2] = {8, 10};
  double col_lower[2] = {0, 0};
  double col_upper[2] = {inf, inf};
  double row_lower[2] = {-inf, -inf};
  double row_upper[2] = {120, 210};
  HighsInt a_index[4] = {0, 1, 0, 1};
  double a_value[4] = {0.3, 0.5, 0.7, 0.5};
  HighsInt a_start[2] = {0, 2};
  Highs_addVars(highs, num_col, col_lower, col_upper);
  Highs_changeColsCostByRange(highs, 0, num_col - 1, col_cost);
  Highs_addRows(highs, num_row, row_lower, row_upper, num_nz, a_start, a_index,
                a_value);
  Highs_changeObjectiveSense(highs, sense);

  assert(Highs_getNumCols(highs) == num_col);
  assert(Highs_getNumRows(highs) == num_row);
  assert(Highs_getNumNz(highs) == num_nz);
  assert(Highs_getHessianNumNz(highs) == 0);

  HighsInt ck_num_col;
  HighsInt ck_num_row;
  HighsInt ck_num_nz;
  HighsInt ck_sense;
  double ck_offset;
  HighsInt a_format = kHighsMatrixFormatRowwise;

  // Get the model dimensions by passing array pointers as NULL
  HighsInt return_status;
  return_status = Highs_getLp(highs, a_format, &ck_num_col, &ck_num_row,
              &ck_num_nz, &ck_sense, &ck_offset, NULL, NULL, NULL, NULL, NULL,
              NULL, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);

  assert(ck_num_col == num_col);
  assert(ck_num_row == num_row);
  assert(ck_num_nz == num_nz);
  // Motivated by #1712, ensure that the correct sense is returned when
  // maximizing
  assert(ck_sense == sense);

  double* ck_col_cost = (double*)malloc(sizeof(double) * ck_num_col);
  double* ck_col_lower = (double*)malloc(sizeof(double) * ck_num_col);
  double* ck_col_upper = (double*)malloc(sizeof(double) * ck_num_col);
  double* ck_row_lower = (double*)malloc(sizeof(double) * ck_num_row);
  double* ck_row_upper = (double*)malloc(sizeof(double) * ck_num_row);
  HighsInt* ck_a_start = (HighsInt*)malloc(sizeof(HighsInt) * ck_num_col);
  HighsInt* ck_a_index = (HighsInt*)malloc(sizeof(HighsInt) * ck_num_nz);
  double* ck_a_value = (double*)malloc(sizeof(double) * num_nz);

  // Get the arrays
  return_status = Highs_getLp(highs, a_format, &ck_num_col, &ck_num_row,
              &ck_num_nz, &ck_sense, &ck_offset, ck_col_cost, ck_col_lower,
              ck_col_upper, ck_row_lower, ck_row_upper, ck_a_start, ck_a_index,
              ck_a_value, NULL);
  assert(return_status == kHighsStatusOk);

  assert(doubleArraysEqual(num_col, ck_col_cost, col_cost));
  assert(doubleArraysEqual(num_col, ck_col_lower, col_lower));
  assert(doubleArraysEqual(num_col, ck_col_upper, col_upper));
  assert(doubleArraysEqual(num_row, ck_row_lower, row_lower));
  assert(doubleArraysEqual(num_row, ck_row_upper, row_upper));
  assert(highsIntArraysEqual(num_col, ck_a_start, a_start));
  assert(highsIntArraysEqual(num_nz, ck_a_index, a_index));
  assert(doubleArraysEqual(num_nz, ck_a_value, a_value));

  return_status = Highs_getModel(
      highs, a_format, 0, &ck_num_col, &ck_num_row, &ck_num_nz, NULL, &ck_sense,
      &ck_offset, ck_col_cost, ck_col_lower,
      ck_col_upper, ck_row_lower, ck_row_upper, ck_a_start, ck_a_index,
      ck_a_value, NULL, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);

  assert(ck_num_col == num_col);
  assert(ck_num_row == num_row);
  assert(ck_num_nz == num_nz);
  assert(ck_sense == sense);
  assert(doubleArraysEqual(num_col, ck_col_cost, col_cost));
  assert(doubleArraysEqual(num_col, ck_col_lower, col_lower));
  assert(doubleArraysEqual(num_col, ck_col_upper, col_upper));
  assert(doubleArraysEqual(num_row, ck_row_lower, row_lower));
  assert(doubleArraysEqual(num_row, ck_row_upper, row_upper));
  assert(highsIntArraysEqual(num_col, ck_a_start, a_start));
  assert(highsIntArraysEqual(num_nz, ck_a_index, a_index));
  assert(doubleArraysEqual(num_nz, ck_a_value, a_value));

  Highs_destroy(highs);
}

void testMultiObjective() {
  void* highs;
  highs = Highs_create();
  const double inf = Highs_getInfinity(highs);

  HighsInt num_col = 2;
  HighsInt num_row = 3;
  HighsInt num_nz = num_col * num_row;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMaximize;
  double offset = -1;
  double col_cost[2] = {1, 1};
  double col_lower[2] = {0, 0};
  double col_upper[2] = {inf, inf};
  double row_lower[3] = {-inf, -inf, -inf};
  double row_upper[3] = {18, 8, 14};
  HighsInt a_start[3] = {0, 3, 6};
  HighsInt a_index[6] = {0, 1, 2, 0, 1, 2};
  double a_value[6] = {3, 1, 1, 1, 1, 2};

  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt return_status = Highs_passLp(
      highs, num_col, num_row, num_nz, a_format, sense, offset, col_cost,
      col_lower, col_upper, row_lower, row_upper, a_start, a_index, a_value);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_clearLinearObjectives(highs);
  assert(return_status == kHighsStatusOk);

  double weight = -1;
  double linear_objective_offset = -1;
  double coefficients[2] = {1, 1};
  double abs_tolerance = 0;
  double rel_tolerance = 0;
  HighsInt priority = 10;
  return_status = Highs_addLinearObjective(
      highs, weight, linear_objective_offset, coefficients, abs_tolerance,
      rel_tolerance, priority);
  assert(return_status == kHighsStatusOk);

  weight = 1e-4;
  linear_objective_offset = 0;
  coefficients[0] = 1;
  coefficients[1] = 0;
  priority = 0;
  return_status = Highs_addLinearObjective(
      highs, weight, linear_objective_offset, coefficients, abs_tolerance,
      rel_tolerance, priority);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  HighsInt model_status = Highs_getModelStatus(highs);
  assert(model_status == kHighsModelStatusOptimal);

  Highs_writeSolutionPretty(highs, "");
  double* col_value = (double*)malloc(sizeof(double) * num_col);
  return_status = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 2);
  assertDoubleValuesEqual("col_value[1]", col_value[1], 6);

  Highs_setBoolOptionValue(highs, "blend_multi_objectives", 0);

  if (dev_run) printf("\n***************\nLexicographic 1\n***************\n");
  double weight2[2] = {-1, 1e-4};
  double linear_objective_offset2[2] = {-1, 0};
  double coefficients2[4] = {1, 1, 1, 0};
  double abs_tolerance2[2] = {0, -1};
  double rel_tolerance2[2] = {0, -1};
  HighsInt priority2[2] = {10, 0};
  return_status = Highs_passLinearObjectives(
      highs, 2, weight2, linear_objective_offset2, coefficients2,
      abs_tolerance2, rel_tolerance2, priority2);
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  model_status = Highs_getModelStatus(highs);
  assert(model_status == kHighsModelStatusOptimal);
  Highs_writeSolutionPretty(highs, "");
  return_status = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 2);
  assertDoubleValuesEqual("col_value[1]", col_value[1], 6);

  //  weight2[1] = 1e-5;
  coefficients2[0] = 1.0001;
  abs_tolerance2[0] = 1e-5;
  rel_tolerance2[0] = 0.05;
  return_status = Highs_passLinearObjectives(
      highs, 2, weight2, linear_objective_offset2, coefficients2,
      abs_tolerance2, rel_tolerance2, priority2);
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  model_status = Highs_getModelStatus(highs);
  assert(model_status == kHighsModelStatusOptimal);
  Highs_writeSolutionPretty(highs, "");
  return_status = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 4.9);
  assertDoubleValuesEqual("col_value[1]", col_value[1], 3.1);

  if (dev_run) printf("\n***************\nLexicographic 2\n***************\n");
  abs_tolerance2[0] = -1;

  return_status = Highs_passLinearObjectives(
      highs, 2, weight2, linear_objective_offset2, coefficients2,
      abs_tolerance2, rel_tolerance2, priority2);
  return_status = Highs_run(highs);
  assert(return_status == kHighsStatusOk);
  model_status = Highs_getModelStatus(highs);
  assert(model_status == kHighsModelStatusOptimal);
  Highs_writeSolutionPretty(highs, "");
  return_status = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 1.30069);
  assertDoubleValuesEqual("col_value[1]", col_value[1], 6.34966);

  Highs_destroy(highs);
  free(col_value);
}

void testQpIndefiniteFailure() {
  void* highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt ret;
  const double inf = Highs_getInfinity(highs);
  ret = Highs_addCol(highs, 0.0, 1.0, inf, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 1.0, 1.0, 0, NULL, NULL);
  HighsInt start[2] = {0, 1};
  HighsInt index[1] = {1};
  double value[1] = {1.0};
  ret = Highs_passHessian(highs, 2, 1, kHighsHessianFormatTriangular, start,
                          index, value);
  assert(ret == 0);
  HighsInt run_status = Highs_run(highs);
  HighsInt model_status = Highs_getModelStatus(highs);
  assert(run_status == kHighsStatusError);
  assert(model_status == kHighsModelStatusSolveError);
  Highs_destroy(highs);
}

void testDualRayTwice() {
  void* highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  int ret;
  double inf = Highs_getInfinity(highs);
  ret = Highs_changeObjectiveOffset(highs, 0.0);
  assert(ret == 0);
  ret = Highs_setStringOptionValue(highs, "presolve", "off");
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 0.0, 0.0, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 0.0, 0.0, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, -1.0, 0.0, inf, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, -1.0, 0.0, inf, 0, NULL, NULL);
  assert(ret == 0);
  HighsInt index[2] = {2, 3};
  double value[2] = {1.0, -1.0};
  ret = Highs_addRow(highs, 0.0, 0.0, 2, index, value);
  assert(ret == 0);
  index[0] = 2;
  index[1] = 3;
  value[0] = 1.0;
  value[1] = 1.0;
  ret = Highs_addRow(highs, 1.0, inf, 2, index, value);
  assert(ret == 0);
  index[0] = 0;
  index[1] = 2;
  value[0] = -2.0;
  value[1] = 1.0;
  ret = Highs_addRow(highs, -inf, 0.0, 2, index, value);
  assert(ret == 0);
  index[0] = 1;
  index[1] = 3;
  value[0] = -3.0;
  value[1] = 1.0;
  ret = Highs_addRow(highs, -inf, 0.0, 2, index, value);
  assert(ret == 0);
  ret = Highs_run(highs);
  assert(ret == 0);
  HighsInt has_dual_ray = 0;
  double dual_ray_value[4] = {0.0, 0.0, 0.0, 0.0};
  ret = Highs_getDualRay(highs, &has_dual_ray, dual_ray_value);
  assert(ret == 0);
  assertIntValuesEqual("has_dual_ray", has_dual_ray, 1);
  assertDoubleValuesEqual("dual_ray_value[0]", dual_ray_value[0], 0.0);
  assertDoubleValuesEqual("dual_ray_value[1]", dual_ray_value[1], 1.0);
  assertDoubleValuesEqual("dual_ray_value[2]", dual_ray_value[2], -1.0);
  assertDoubleValuesEqual("dual_ray_value[3]", dual_ray_value[3], -1.0);
  ret = Highs_changeColBounds(highs, 1, 1.0, 1.0);
  assert(ret == 0);
  ret = Highs_run(highs);
  assert(ret == 0);
  ret = Highs_getDualRay(highs, &has_dual_ray, dual_ray_value);
  assert(ret == 0);
  assertIntValuesEqual("has_dual_ray", has_dual_ray, 1);
  assertDoubleValuesEqual("dual_ray_value[0]", dual_ray_value[0], 1.0);
  assertDoubleValuesEqual("dual_ray_value[1]", dual_ray_value[1], 1.0);
  assertDoubleValuesEqual("dual_ray_value[2]", dual_ray_value[2], -2.0);
  assertDoubleValuesEqual("dual_ray_value[3]", dual_ray_value[3], 0.0);
  Highs_destroy(highs);
  return;
}

/*
The horrible C in this causes problems in some of the CI tests,
so suppress thius test until the C has been improved

void testSetSolution() {
  void* highs = Highs_create();
  // Perform in C the equivalent of std::string model_file =
  // std::string(HIGHS_DIR) + "/check/instances/shell.mps";

  char* dir = HIGHS_DIR;
  char model_file0[100];
  strcat(model_file0, dir);
  strcat(model_file0, "/check/instances/shell.mps");
  strcat(model_file0, "\0");
  char* substr = model_file0 + 1;
  memmove(model_file0, substr, strlen(substr) + 1);
  HighsInt length = strlen(model_file0) + 1;
  char model_file[length];
  strcpy(model_file, model_file0);

  if (dev_run) printf("\nSolving from scratch\n");
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);

  Highs_readModel(highs, model_file);
  Highs_run(highs);
 HighsInt iteration_count0;
  Highs_getIntInfoValue(highs, "simplex_iteration_count", &iteration_count0);
 HighsInt num_col = Highs_getNumCol(highs);
  double* col_value = (double*)malloc(sizeof(double) * num_col);
  Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  Highs_clear(highs);
  if (dev_run) printf("\nSolving from saved solution\n");
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  Highs_readModel(highs, model_file);
  Highs_setSolution(highs, col_value, NULL, NULL, NULL);
  Highs_run(highs);
  HighsInt iteration_count1;
  Highs_getIntInfoValue(highs, "simplex_iteration_count", &iteration_count1);
  HighsInt logic = iteration_count0 > iteration_count1;
  printf("Iteration counts are %d and %d\n", iteration_count0,
iteration_count1); assertLogical("Dual", logic);

  Highs_destroy(highs);
}
*/
void testDeleteRowResolveWithBasis() {
  // Created to expose bug in #2267, but also illustrates case where
  // scaling was performed on the original problem - due to the 6 in
  // row 1, but would not be performed on the problem after row 1 has
  // been removed
  void* highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt ret;
  double inf = Highs_getInfinity(highs);
  ret = Highs_addCol(highs, 0.0, 2.0, 2.0, 0, NULL, NULL);
  ret = Highs_addCol(highs, 0.0, -inf, inf, 0, NULL, NULL);
  ret = Highs_addCol(highs, 0.0, -inf, inf, 0, NULL, NULL);
  HighsInt index_1[2] = {0, 2};
  double value_1[2] = {2.0, -1.0};
  ret = Highs_addRow(highs, 0.0, 0.0, 2, index_1, value_1);
  HighsInt index_2[1] = {1};
  double value_2[1] = {6.0};
  ret = Highs_addRow(highs, 10.0, inf, 1, index_2, value_2);
  Highs_run(highs);
  double col_value[3] = {0.0, 0.0, 0.0};
  Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 2.0);
  ret = Highs_deleteRowsByRange(highs, 1, 1);
  assert(ret == 0);
  ret = Highs_run(highs);
  assert(ret == 0);
  ret = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assert(ret == 0);
  assertDoubleValuesEqual("col_value[0]", col_value[0], 2.0);
  Highs_destroy(highs);
}

void testIis() {
  void* highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  HighsInt ret;
  double inf = Highs_getInfinity(highs);
  // For the constraints
  //
  // x + y - z = 2
  //
  // x + y + z <= 5
  //
  // x + 2y + z <= 1
  //
  // with variables in [0, 1], constraints 0 and 2 form an IIS with
  // 
  // x free; 0 <= y; 0 <= z
  //
  // x + y - z >= 2; x + 2y + z <= 1
  //
  // x may be free, but can't immediately be removed, otherwise
  // removing y >= 0 yields an infeasible LP
  //
  ret = Highs_addCol(highs, 0.0, 0.0, 1.0, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 0.0, 1.0, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 0.0, 1.0, 0, NULL, NULL);
  assert(ret == 0);
  HighsInt index[3] = {0, 1, 2};
  double value_1[3] = {1, 1, -1};
  double value_2[3] = {1, 1, 1};
  double value_3[3] = {1, 2, 1};
  ret = Highs_addRow(highs,  2.0, 2.0, 3, index, value_1);
  assert(ret == 0);
  ret = Highs_addRow(highs, -inf, 5.0, 3, index, value_2);
  assert(ret == 0);
  ret = Highs_addRow(highs, -inf, 1.0, 3, index, value_3);
  assert(ret == 0);

  HighsInt num_col;
  HighsInt num_row;
  HighsInt num_nz;
  HighsInt sense;
  double offset;
  ret = Highs_getLp(highs, kHighsMatrixFormatRowwise,
		    &num_col, &num_row, &num_nz,
		    &sense, &offset,
		    NULL, NULL, NULL, 
		    NULL, NULL,
		    NULL, NULL, NULL,
		    NULL);

  for (int k = 0 ; k < 2; k++) {
    HighsInt iis_num_col;
    HighsInt iis_num_row;
    ret = Highs_getIis(highs,
		       &iis_num_col, &iis_num_row,
		       NULL, NULL,
		       NULL, NULL,
		       NULL, NULL);
    assert(ret == 0);

    if (k == 0) {
      // No IIS from kHighsIisStrategyLight
      assert(iis_num_col == 0);
      assert(iis_num_row == 0);
      Highs_setIntOptionValue(highs, "iis_strategy",
			      kHighsIisStrategyFromLpRowPriority);
    } else {
      assert(iis_num_col == 3);
      assert(iis_num_row == 2);
      HighsInt* col_index = (HighsInt*)malloc(sizeof(HighsInt) * iis_num_col);
      HighsInt* row_index = (HighsInt*)malloc(sizeof(HighsInt) * iis_num_row);
      HighsInt* col_bound = (HighsInt*)malloc(sizeof(HighsInt) * iis_num_col);
      HighsInt* row_bound = (HighsInt*)malloc(sizeof(HighsInt) * iis_num_row);
      HighsInt* col_status = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
      HighsInt* row_status = (HighsInt*)malloc(sizeof(HighsInt) * num_row);
      ret = Highs_getIis(highs,
			 &iis_num_col, &iis_num_row,
			 col_index, row_index,
			 col_bound, row_bound,
			 col_status, row_status);
      assert(ret == 0);
      
      assert(col_index[0] == 0);
      assert(col_index[1] == 1);
      assert(col_index[2] == 2);

      assert(row_index[0] == 0);
      assert(row_index[1] == 2);

      assert(col_bound[0] == kHighsIisBoundFree);
      assert(col_bound[1] == kHighsIisBoundLower);
      assert(col_bound[2] == kHighsIisBoundLower);

      assert(row_bound[0] == kHighsIisBoundLower);
      assert(row_bound[1] == kHighsIisBoundUpper);

      assert(col_status[0] == kHighsIisStatusInConflict);
      assert(col_status[1] == kHighsIisStatusInConflict);
      assert(col_status[2] == kHighsIisStatusInConflict);
      
      assert(row_status[0] == kHighsIisStatusInConflict);
      assert(row_status[1] == kHighsIisStatusNotInConflict);
      assert(row_status[2] == kHighsIisStatusInConflict);
      
      free(col_index);
      free(row_index);
      free(col_bound);
      free(row_bound);
      free(col_status);
      free(row_status);
    }
  }

  // Re #2635 check with feasible LP
  Highs_clearModel(highs);

  ret = Highs_addCol(highs, 0.0, 0.0, inf, 0, NULL, NULL);
  assert(ret == 0);
  ret = Highs_addCol(highs, 0.0, 0.0, inf, 0, NULL, NULL);
  assert(ret == 0);
  index[0] = 0;
  index[1] = 1;
  value_1[0] = 1;
  value_1[1] = 2;
  value_2[0] = 1;
  value_2[1] = 4;
  ret = Highs_addRow(highs, -inf, 80, 2, index, value_1);
  assert(ret == 0);
  ret = Highs_addRow(highs, -inf, 120, 2, index, value_2);
  assert(ret == 0);

  ret = Highs_getLp(highs, kHighsMatrixFormatRowwise,
		    &num_col, &num_row, &num_nz,
		    &sense, &offset,
		    NULL, NULL, NULL, 
		    NULL, NULL,
		    NULL, NULL, NULL,
		    NULL);

  HighsInt* col_index = NULL;
  HighsInt* row_index = NULL;
  HighsInt* col_bound = NULL;
  HighsInt* row_bound = NULL;
  HighsInt* col_status = (HighsInt*)malloc(sizeof(HighsInt) * num_col);
  HighsInt* row_status = (HighsInt*)malloc(sizeof(HighsInt) * num_row);

  // First try with kIisStrategyLight
  Highs_setIntOptionValue(highs, "iis_strategy", kHighsIisStrategyLight);
  
  for (int k = 0 ; k < 2; k++) {
    HighsInt iis_num_col;
    HighsInt iis_num_row;
    ret = Highs_getIis(highs,
		       &iis_num_col, &iis_num_row,
		       NULL, NULL,
		       NULL, NULL,
		       NULL, NULL);
    assert(ret == 0);

    assert(iis_num_col == 0);
    assert(iis_num_row == 0);
    ret = Highs_getIis(highs,
		       &iis_num_col, &iis_num_row,
		       col_index, row_index,
		       col_bound, row_bound,
		       col_status, row_status);
    assert(ret == 0);
    if (k == 0) {
      // Before running HiGHS, model status is unknown
      assert(col_status[0] == kHighsIisStatusMaybeInConflict);
      assert(col_status[1] == kHighsIisStatusMaybeInConflict);
      assert(row_status[0] == kHighsIisStatusMaybeInConflict);
      assert(row_status[1] == kHighsIisStatusMaybeInConflict);
    } else {
      // After running HiGHS, model status is known to be optimal
      assert(col_status[0] == kHighsIisStatusNotInConflict);
      assert(col_status[1] == kHighsIisStatusNotInConflict);
      assert(row_status[0] == kHighsIisStatusNotInConflict);
      assert(row_status[1] == kHighsIisStatusNotInConflict);
    }
    Highs_run(highs);
  }

  // Now try with kHighsIisStrategyFromLpRowPriority
  Highs_clearSolver(highs);
  Highs_setIntOptionValue(highs, "iis_strategy",
			  kHighsIisStrategyFromLpRowPriority);
  HighsInt iis_num_col;
  HighsInt iis_num_row;
  ret = Highs_getIis(highs,
		     &iis_num_col, &iis_num_row,
		     NULL, NULL,
		     NULL, NULL,
		     NULL, NULL);
  assert(ret == 0);

  assert(iis_num_col == 0);
  assert(iis_num_row == 0);
  ret = Highs_getIis(highs,
		     &iis_num_col, &iis_num_row,
		     col_index, row_index,
		     col_bound, row_bound,
		     col_status, row_status);
  assert(ret == 0);
  // With kHighsIisStrategyFromLpRowPriority, model status is found to
  // be feasible
  assert(col_status[0] == kHighsIisStatusNotInConflict);
  assert(col_status[1] == kHighsIisStatusNotInConflict);
  assert(row_status[0] == kHighsIisStatusNotInConflict);
  assert(row_status[1] == kHighsIisStatusNotInConflict);

  free(col_status);
  free(row_status);

  Highs_destroy(highs);
}

void testFixedLp() {
  // The use of Highs_getFixedLp is illustrated for the MIP
  //
  // Min    f  = -3x_0 - 2x_1 - x_2
  // s.t.          x_0 +  x_1 + x_2 <=  7
  //              4x_0 + 2x_1 + x_2  = 12
  //              x_0 >=0; x_1 >= 0; x_2 binary

  const HighsInt num_col = 3;
  const HighsInt num_row = 2;
  const HighsInt num_nz = 6;
  HighsInt a_format = kHighsMatrixFormatColwise;
  HighsInt sense = kHighsObjSenseMinimize;
  double offset = 0;

  // Define the column costs, lower bounds and upper bounds
  double col_cost[3] = {-3.0, -2.0, -1.0};
  double col_lower[3] = {0.0, 0.0, 0.0};
  double col_upper[3] = {1.0e30, 1.0e30, 1.0};
  // Define the row lower bounds and upper bounds
  double row_lower[2] = {-1.0e30, 12.0};
  double row_upper[2] = {7.0, 12.0};
  // Define the constraint matrix column-wise
  HighsInt a_start[3] = {0, 2, 4};
  HighsInt a_index[6] = {0, 1, 0, 1, 0, 1};
  double a_value[6] = {1.0, 4.0, 1.0, 2.0, 1.0, 1.0};
  HighsInt integrality[3] = {kHighsVarTypeContinuous, kHighsVarTypeContinuous,
                             kHighsVarTypeInteger};

  void* highs = Highs_create();
  Highs_setBoolOptionValue(highs, "output_flag", dev_run);
  Highs_setStringOptionValue(highs, "presolve", "off");
  HighsInt return_status =
    Highs_passMip(highs, num_col, num_row, num_nz, a_format, sense, offset,
		  col_cost, col_lower, col_upper, row_lower, row_upper,
		  a_start, a_index, a_value, integrality);
  assert(return_status == kHighsStatusOk);
  return_status = Highs_run(highs);
  double mip_objective_function_value;
  return_status = Highs_getDoubleInfoValue(highs, "objective_function_value",
                                           &mip_objective_function_value);
  assert(return_status == kHighsStatusOk);

  double* col_value = (double*)malloc(sizeof(double) * num_col);
  return_status = Highs_getSolution(highs, col_value, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);

  HighsInt fixed_lp_num_col;
  HighsInt fixed_lp_num_row;
  HighsInt fixed_lp_num_nz;
  HighsInt fixed_lp_sense;
  double fixed_lp_offset;
  Highs_getFixedLp(highs, kHighsMatrixFormatColwise, &fixed_lp_num_col, &fixed_lp_num_row,
		   &fixed_lp_num_nz, &fixed_lp_sense, &fixed_lp_offset, NULL, NULL, NULL, NULL, NULL,
		   NULL, NULL, NULL);

  assert(fixed_lp_num_col == num_col);
  assert(fixed_lp_num_row == num_row);
  assert(fixed_lp_num_nz == num_nz);
  assert(fixed_lp_sense == sense);

  double* fixed_lp_col_cost = (double*)malloc(sizeof(double) * fixed_lp_num_col);
  double* fixed_lp_col_lower = (double*)malloc(sizeof(double) * fixed_lp_num_col);
  double* fixed_lp_col_upper = (double*)malloc(sizeof(double) * fixed_lp_num_col);
  double* fixed_lp_row_lower = (double*)malloc(sizeof(double) * fixed_lp_num_row);
  double* fixed_lp_row_upper = (double*)malloc(sizeof(double) * fixed_lp_num_row);
  HighsInt* fixed_lp_a_start = (HighsInt*)malloc(sizeof(HighsInt) * fixed_lp_num_col);
  HighsInt* fixed_lp_a_index = (HighsInt*)malloc(sizeof(HighsInt) * fixed_lp_num_nz);
  double* fixed_lp_a_value = (double*)malloc(sizeof(double) * num_nz);

  // Get the arrays
  Highs_getFixedLp(highs, kHighsMatrixFormatColwise, &fixed_lp_num_col, &fixed_lp_num_row,
		   &fixed_lp_num_nz, &fixed_lp_sense, &fixed_lp_offset, fixed_lp_col_cost, fixed_lp_col_lower,
		   fixed_lp_col_upper, fixed_lp_row_lower, fixed_lp_row_upper, fixed_lp_a_start, fixed_lp_a_index,
		   fixed_lp_a_value);
  
  return_status = Highs_passLp(highs,
			       fixed_lp_num_col, fixed_lp_num_row, fixed_lp_num_nz,
			       kHighsMatrixFormatColwise,
			       fixed_lp_sense, fixed_lp_offset,
			       fixed_lp_col_cost, fixed_lp_col_lower, fixed_lp_col_upper,
			       fixed_lp_row_lower, fixed_lp_row_upper,
			       fixed_lp_a_start, fixed_lp_a_index, fixed_lp_a_value);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_setSolution(highs, col_value, NULL, NULL, NULL);
  assert(return_status == kHighsStatusOk);

  return_status = Highs_run(highs);
  double objective_function_value;
  return_status = Highs_getDoubleInfoValue(highs, "objective_function_value",
                                           &objective_function_value);
  assert(return_status == kHighsStatusOk);
  assert(objective_function_value == mip_objective_function_value);
  
 
  free(col_value);
  free(fixed_lp_col_cost);
  free(fixed_lp_col_lower);
  free(fixed_lp_col_upper);
  free(fixed_lp_row_lower);
  free(fixed_lp_row_upper);
  free(fixed_lp_a_start);
  free(fixed_lp_a_index);
  free(fixed_lp_a_value);
  
  Highs_destroy(highs);
}

int main() {
  minimalApiIllegalLp();
  testCallback();
  versionApi();
  minimalApiLp();
  minimalApiMip();
  minimalApiQp();
  fullApiOptions();
  fullApiLp();
  fullApiMip();
  fullApiQp();
  passPresolveGetLp();
  options();
  testGetColsByRange();
  testPassHessian();
  testRanging();
  testFeasibilityRelaxation();
  testNames();
  testGetModel();
  testMultiObjective();
  testQpIndefiniteFailure();
  testDualRayTwice();
  testDeleteRowResolveWithBasis();
  testIis();
  testFixedLp();
  return 0;
}
//  testSetSolution();