97 lines
2.5 KiB
C#
97 lines
2.5 KiB
C#
//
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// Copyright 2012 Hakan Kjellerstrand
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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using System;
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using Google.OrTools.ConstraintSolver;
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public class Map
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{
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/**
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*
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* Solves a simple map coloring problem.
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*
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* See http://www.hakank.org/google_or_tools/map.py
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*
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*/
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private static void Solve()
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{
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Solver solver = new Solver("Map");
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//
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// data
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//
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int Belgium = 0;
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int Denmark = 1;
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int France = 2;
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int Germany = 3;
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int Netherlands = 4;
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int Luxembourg = 5;
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int n = 6;
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int max_num_colors = 4;
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//
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// Decision variables
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//
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IntVar[] color = solver.MakeIntVarArray(n, 1, max_num_colors, "color");
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//
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// Constraints
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//
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solver.Add(color[France] != color[Belgium]);
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solver.Add(color[France] != color[Luxembourg]);
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solver.Add(color[France] != color[Germany]);
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solver.Add(color[Luxembourg] != color[Germany]);
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solver.Add(color[Luxembourg] != color[Belgium]);
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solver.Add(color[Belgium] != color[Netherlands]);
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solver.Add(color[Belgium] != color[Germany]);
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solver.Add(color[Germany] != color[Netherlands]);
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solver.Add(color[Germany] != color[Denmark]);
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// Symmetry breaking
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solver.Add(color[Belgium] == 1);
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//
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// Search
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//
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DecisionBuilder db = solver.MakePhase(color,
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Solver.CHOOSE_MIN_SIZE_LOWEST_MAX,
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Solver.ASSIGN_CENTER_VALUE);
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solver.NewSearch(db);
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while (solver.NextSolution()) {
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Console.Write("colors: ");
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for(int i = 0; i < n; i++) {
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Console.Write("{0} ", color[i].Value());
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}
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Console.WriteLine();
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}
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Console.WriteLine("\nSolutions: {0}", solver.Solutions());
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Console.WriteLine("WallTime: {0} ms", solver.WallTime());
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Console.WriteLine("Failures: {0}", solver.Failures());
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Console.WriteLine("Branches: {0} ", solver.Branches());
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solver.EndSearch();
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}
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public static void Main(String[] args)
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{
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Solve();
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}
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}
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