issue22.cs

// Copyright 2010-2022 Google LLC
// 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 System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using Google.OrTools.ConstraintSolver;

public class Issue22Test
{
    private static long Solve(long num_buses_check = 0)
    {
        ConstraintSolverParameters sPrm = Solver.DefaultSolverParameters();
        sPrm.CompressTrail = 0;
        Solver solver = new Solver("OrTools", sPrm);

        // this works
        // IntVar[,] x = solver.MakeIntVarMatrix(2,2, new int[] {-2,0,1,2}, "x");

        // this doesn't work
        IntVar[,] x = solver.MakeIntVarMatrix(2, 2, new int[] { 0, 1, 2 }, "x");

        for (int w = 0; w < 2; w++)
        {
            IntVar[] b = new IntVar[2];
            for (int i = 0; i < 2; i++)
            {
                b[i] = solver.MakeIsEqualCstVar(x[w, i], 0);
            }
            solver.Add(solver.MakeSumGreaterOrEqual(b, 2));
        }

        IntVar[] x_flat = x.Flatten();
        DecisionBuilder db = solver.MakePhase(x_flat, Solver.CHOOSE_FIRST_UNBOUND, Solver.ASSIGN_MIN_VALUE);
        solver.NewSearch(db);
        while (solver.NextSolution())
        {
            Console.WriteLine("x: ");
            for (int j = 0; j < 2; j++)
            {
                Console.Write("worker" + (j + 1).ToString() + ":");
                for (int i = 0; i < 2; i++)
                {
                    Console.Write(" {0,2} ", x[j, i].Value());
                }
                Console.Write("\n");
            }
            Console.WriteLine("End   at---->" + DateTime.Now);
        }

        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();
        return 1;
    }

    public static void InitialPropagateTest()
    {
        Console.WriteLine("Check for minimum number of buses: ");
        long num_buses = Solve();
        Console.WriteLine("\n... got {0} as minimal value.", num_buses);
        Console.WriteLine("\nAll solutions: ", num_buses);
    }

    static void Main()
    {
        InitialPropagateTest();
    }
}