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//
// Copyright 2012 Hakan Kjellerstrand
//
// 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.
using System;
using Google.OrTools.ConstraintSolver;
public class Map
{
/**
*
* Solves a simple map coloring problem.
*
* See http://www.hakank.org/google_or_tools/map.py
*
*/
private static void Solve()
{
Solver solver = new Solver("Map");
//
// data
//
int Belgium = 0;
int Denmark = 1;
int France = 2;
int Germany = 3;
int Netherlands = 4;
int Luxembourg = 5;
int n = 6;
int max_num_colors = 4;
//
// Decision variables
//
IntVar[] color = solver.MakeIntVarArray(n, 1, max_num_colors, "color");
//
// Constraints
//
solver.Add(color[France] != color[Belgium]);
solver.Add(color[France] != color[Luxembourg]);
solver.Add(color[France] != color[Germany]);
solver.Add(color[Luxembourg] != color[Germany]);
solver.Add(color[Luxembourg] != color[Belgium]);
solver.Add(color[Belgium] != color[Netherlands]);
solver.Add(color[Belgium] != color[Germany]);
solver.Add(color[Germany] != color[Netherlands]);
solver.Add(color[Germany] != color[Denmark]);
// Symmetry breaking
solver.Add(color[Belgium] == 1);
//
// Search
//
DecisionBuilder db = solver.MakePhase(color, Solver.CHOOSE_MIN_SIZE_LOWEST_MAX, Solver.ASSIGN_CENTER_VALUE);
solver.NewSearch(db);
while (solver.NextSolution())
{
Console.Write("colors: ");
for (int i = 0; i < n; i++)
{
Console.Write("{0} ", color[i].Value());
}
Console.WriteLine();
}
Console.WriteLine("\nSolutions: {0}", solver.Solutions());
Console.WriteLine("WallTime: {0} ms", solver.WallTime());
Console.WriteLine("Failures: {0}", solver.Failures());
Console.WriteLine("Branches: {0} ", solver.Branches());
solver.EndSearch();
}
public static void Main(String[] args)
{
Solve();
}
}