121 lines
3.2 KiB
C#
121 lines
3.2 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 System.Collections;
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using System.IO;
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using System.Text.RegularExpressions;
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using Google.OrTools.ConstraintSolver;
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public class GolombRuler
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{
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/**
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*
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* Golomb Ruler problem.
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*
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* This C# implementation is based on Charles Prud'homme's
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* or-tools/Java model:
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* http://code.google.com/p/or-tools/source/browse/trunk/com/google/ortools/constraintsolver/samples/GolombRuler.java
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*
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*/
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private static void Solve(int m = 8)
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{
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Solver solver = new Solver("GolombRuler");
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//
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// Decision variables
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//
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IntVar[] ticks = solver.MakeIntVarArray(m, 0, ((m < 31) ? (1 << (m + 1)) - 1 : 9999), "ticks");
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IntVar[] diff = new IntVar[(m * m - m) / 2];
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//
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// Constraints
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//
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solver.Add(ticks[0] == 0);
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for (int i = 0; i < ticks.Length - 1; i++)
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{
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solver.Add(ticks[i] < ticks[i + 1]);
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}
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for (int k = 0, i = 0; i < m - 1; i++)
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{
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for (int j = i + 1; j < m; j++, k++)
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{
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diff[k] = (ticks[j] - ticks[i]).Var();
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solver.Add(diff[k] >= (j - i) * (j - i + 1) / 2);
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}
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}
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solver.Add(diff.AllDifferent());
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// break symetries
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if (m > 2)
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{
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solver.Add(diff[0] < diff[diff.Length - 1]);
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}
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//
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// Optimization
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//
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OptimizeVar opt = ticks[m - 1].Minimize(1);
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//
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// Search
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//
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DecisionBuilder db = solver.MakePhase(ticks, Solver.CHOOSE_MIN_SIZE_LOWEST_MIN, Solver.ASSIGN_MIN_VALUE);
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// We just want the debug info for larger instances.
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if (m >= 11)
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{
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SearchMonitor log = solver.MakeSearchLog(10000, opt);
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solver.NewSearch(db, opt, log);
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}
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else
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{
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solver.NewSearch(db, opt);
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}
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while (solver.NextSolution())
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{
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Console.Write("opt: {0} [ ", ticks[m - 1].Value());
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for (int i = 0; i < m; i++)
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{
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Console.Write("{0} ", ticks[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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int n = 8;
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if (args.Length > 1)
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{
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n = Convert.ToInt32(args[1]);
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}
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Solve(n);
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}
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}
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