Files
ortools-clone/examples/csharp/strimko2.cs
2012-03-28 14:23:23 +00:00

134 lines
3.4 KiB
C#

//
// 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 System.Collections;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using Google.OrTools.ConstraintSolver;
public class Strimko2
{
/**
*
* Solves a Strimko problem.
* See http://www.hakank.org/google_or_tools/strimko2.py
*
*/
private static void Solve()
{
Solver solver = new Solver("Strimko2");
//
// data
//
int[,] streams = {{1,1,2,2,2,2,2},
{1,1,2,3,3,3,2},
{1,4,1,3,3,5,5},
{4,4,3,1,3,5,5},
{4,6,6,6,7,7,5},
{6,4,6,4,5,5,7},
{6,6,4,7,7,7,7}};
// Note: This is 1-based
int[,] placed = {{2,1,1},
{2,3,7},
{2,5,6},
{2,7,4},
{3,2,7},
{3,6,1},
{4,1,4},
{4,7,5},
{5,2,2},
{5,6,6}};
int n = streams.GetLength(0);
int num_placed = placed.GetLength(0);
//
// Decision variables
//
IntVar[,] x = solver.MakeIntVarMatrix(n, n, 1, n, "x");
IntVar[] x_flat = x.Flatten();
//
// Constraints
//
// all rows and columns must be unique, i.e. a Latin Square
for(int i = 0; i < n; i++) {
IntVar[] row = new IntVar[n];
IntVar[] col = new IntVar[n];
for(int j = 0; j < n; j++) {
row[j] = x[i,j];
col[j] = x[j,i];
}
solver.Add(row.AllDifferent());
solver.Add(col.AllDifferent());
}
// streams
for(int s = 1; s <= n; s++) {
IntVar[] tmp = (from i in Enumerable.Range(0, n)
from j in Enumerable.Range(0, n)
where streams[i,j] == s
select x[i,j]).ToArray();
solver.Add(tmp.AllDifferent());
}
// placed
for(int i = 0; i < num_placed; i++) {
// note: also adjust to 0-based
solver.Add(x[placed[i,0] - 1,placed[i,1] - 1] == placed[i,2]);
}
//
// Search
//
DecisionBuilder db = solver.MakePhase(x_flat,
Solver.INT_VAR_DEFAULT,
Solver.INT_VALUE_DEFAULT);
solver.NewSearch(db);
while (solver.NextSolution()) {
for(int i = 0; i < n; i++) {
for(int j = 0; j < n; j++) {
Console.Write(x[i,j].Value() + " ");
}
Console.WriteLine();
}
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();
}
}