Files
ortools-clone/examples/contrib/sudoku.cs
2020-11-03 10:15:53 +01:00

125 lines
3.5 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.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using Google.OrTools.ConstraintSolver;
public class Sudoku
{
/**
*
* Solves a Sudoku problem.
*
*/
private static void Solve()
{
Solver solver = new Solver("Sudoku");
//
// data
//
int cell_size = 3;
IEnumerable<int> CELL = Enumerable.Range(0, cell_size);
int n = cell_size * cell_size;
IEnumerable<int> RANGE = Enumerable.Range(0, n);
// 0 marks an unknown value
int[,] initial_grid = { { 0, 6, 0, 0, 5, 0, 0, 2, 0 }, { 0, 0, 0, 3, 0, 0, 0, 9, 0 },
{ 7, 0, 0, 6, 0, 0, 0, 1, 0 }, { 0, 0, 6, 0, 3, 0, 4, 0, 0 },
{ 0, 0, 4, 0, 7, 0, 1, 0, 0 }, { 0, 0, 5, 0, 9, 0, 8, 0, 0 },
{ 0, 4, 0, 0, 0, 1, 0, 0, 6 }, { 0, 3, 0, 0, 0, 8, 0, 0, 0 },
{ 0, 2, 0, 0, 4, 0, 0, 5, 0 } };
//
// Decision variables
//
IntVar[,] grid = solver.MakeIntVarMatrix(n, n, 1, 9, "grid");
IntVar[] grid_flat = grid.Flatten();
//
// Constraints
//
// init
foreach (int i in RANGE)
{
foreach (int j in RANGE)
{
if (initial_grid[i, j] > 0)
{
solver.Add(grid[i, j] == initial_grid[i, j]);
}
}
}
foreach (int i in RANGE)
{
// rows
solver.Add((from j in RANGE select grid[i, j]).ToArray().AllDifferent());
// cols
solver.Add((from j in RANGE select grid[j, i]).ToArray().AllDifferent());
}
// cells
foreach (int i in CELL)
{
foreach (int j in CELL)
{
solver.Add((from di in CELL from dj in CELL select grid[i * cell_size + di, j * cell_size + dj])
.ToArray()
.AllDifferent());
}
}
//
// Search
//
DecisionBuilder db = solver.MakePhase(grid_flat, Solver.INT_VAR_SIMPLE, Solver.INT_VALUE_SIMPLE);
solver.NewSearch(db);
while (solver.NextSolution())
{
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
Console.Write("{0} ", grid[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();
}
}