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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* */
/* This file is part of the program and library */
/* SCIP --- Solving Constraint Integer Programs */
/* */
/* Copyright 2002-2022 Zuse Institute Berlin */
/* */
/* Licensed under the Apache License, Version 2.0 (the "License"); */
/* you may not use this file except in compliance with the License. */
/* You may obtain a copy of the License at */
/* */
/* http://www.apache.org/licenses/LICENSE-2.0 */
/* */
/* Unless required by applicable law or agreed to in writing, software */
/* distributed under the License is distributed on an "AS IS" BASIS, */
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
/* See the License for the specific language governing permissions and */
/* limitations under the License. */
/* */
/* You should have received a copy of the Apache-2.0 license */
/* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
/* */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/**@file reader_dec.h
* @ingroup FILEREADERS
* @brief file reader for decompositions in the constraint based dec-file format.
* @author Gregor Hendel
*
*
* This reader allows to read a file containing decompositions for constraints of the current original problem. The
* standard line ending for this format is '.dec'. The content of the file should obey the following format
*
* \\ place for comments and statistics
* NBLOCKS
* 2
* BLOCK 0
* consA
* consB
* [...]
* BLOCK 1
* consC
* consD
* [...]
* MASTERCONSS
* linkingcons
*
* A block in a problem decomposition is a set of constraints that are independent from all other blocks after removing
* the special blocks of linking constraints denoted as MASTERCONSS.
*
* Imagine the following example, which involves seven variables
* and the five constraints from the file above. The asterisks (*) indicate that the variable affects the feasibility
* of the constraint. In the special case of a linear optimization problem, the asterisks correspond to the
* nonzero entries of the constraint matrix.
*
* x1 x2 x3 x4 x5 x6 x7
* consA * * \ BLOCK 0
* consB * * /
* consC * * \ BLOCK 1
* consD * * /
* linkingconss * * * * * * * > MASTERCONSS
*
* The nonzero pattern has been chosen in a way that after the removal of the last constraint 'linkingcons', the remaining problem
* consists of two independent parts, namely the blocks '0' and '1'.
*
* The corresponding variable labels are inferred from the constraint labels. A variable is assigned the label
*
* - of its unique block, if it only occurs in exactly 1 named block, and probably in MASTERCONSS.
* - the special label of a linking variable if it occurs only in the master constraints or in 2 or even more named blocks.
*
* @note A trivial decomposition is to assign all constraints of a problem to the MASTERCONSS.
*
* @note The number of blocks is the number of named blocks: a trivial decomposition should have 0 blocks
*/
/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
#ifndef __SCIP_READER_DEC_H__
#define __SCIP_READER_DEC_H__
#include "scip/def.h"
#include "scip/type_retcode.h"
#include "scip/type_scip.h"
#ifdef __cplusplus
extern "C" {
#endif
/** includes the decomposition file reader into SCIP
*
* @ingroup FileReaderIncludes
*/
SCIP_EXPORT
SCIP_RETCODE SCIPincludeReaderDec(
SCIP* scip /**< SCIP data structure */
);
#ifdef __cplusplus
}
#endif
#endif