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

232 lines
7.2 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.Linq;
using Google.OrTools.ConstraintSolver;
public class APuzzle
{
/**
*
* From "God plays dice"
* "A puzzle"
* http://gottwurfelt.wordpress.com/2012/02/22/a-puzzle/
* And the sequel "Answer to a puzzle"
* http://gottwurfelt.wordpress.com/2012/02/24/an-answer-to-a-puzzle/
*
* This problem instance was taken from the latter blog post.
* (Problem 1)
*
* """
* 8809 = 6
* 7111 = 0
* 2172 = 0
* 6666 = 4
* 1111 = 0
* 3213 = 0
* 7662 = 2
* 9312 = 1
* 0000 = 4
* 2222 = 0
* 3333 = 0
* 5555 = 0
* 8193 = 3
* 8096 = 5
* 7777 = 0
* 9999 = 4
* 7756 = 1
* 6855 = 3
* 9881 = 5
* 5531 = 0
*
* 2581 = ?
* """
*
* Note:
* This model yields 10 solutions, since x4 is not
* restricted in the constraints.
* All solutions has x assigned to the correct result.
*
*
* (Problem 2)
* The problem stated in "A puzzle"
* http://gottwurfelt.wordpress.com/2012/02/22/a-puzzle/
* is
* """
* 8809 = 6
* 7662 = 2
* 9312 = 1
* 8193 = 3
* 8096 = 5
* 7756 = 1
* 6855 = 3
* 9881 = 5
*
* 2581 = ?
* """
* This problem instance yields two different solutions of x,
* one is the same (correct) as for the above problem instance,
* and one is not.
* This is because here x0,x1,x4 and x9 are underdefined.
*
*
*/
private static void Solve(int p = 1)
{
Solver solver = new Solver("APuzzle");
Console.WriteLine("\nSolving p{0}", p);
//
// Data
//
int n = 10;
//
// Decision variables
//
IntVar x0 = solver.MakeIntVar(0, n - 1, "x0");
IntVar x1 = solver.MakeIntVar(0, n - 1, "x1");
IntVar x2 = solver.MakeIntVar(0, n - 1, "x2");
IntVar x3 = solver.MakeIntVar(0, n - 1, "x3");
IntVar x4 = solver.MakeIntVar(0, n - 1, "x4");
IntVar x5 = solver.MakeIntVar(0, n - 1, "x5");
IntVar x6 = solver.MakeIntVar(0, n - 1, "x6");
IntVar x7 = solver.MakeIntVar(0, n - 1, "x7");
IntVar x8 = solver.MakeIntVar(0, n - 1, "x8");
IntVar x9 = solver.MakeIntVar(0, n - 1, "x9");
IntVar[] all = { x0, x1, x2, x3, x4, x5, x6, x7, x8, x9 };
// The unknown, i.e. 2581 = x
IntVar x = solver.MakeIntVar(0, n - 1, "x");
//
// Constraints
//
// Both problem are here shown in two
// approaches:
// - using equations
// - using a a matrix and Sum of each row
if (p == 1)
{
// Problem 1
solver.Add(x8 + x8 + x0 + x9 == 6);
solver.Add(x7 + x1 + x1 + x1 == 0);
solver.Add(x2 + x1 + x7 + x2 == 0);
solver.Add(x6 + x6 + x6 + x6 == 4);
solver.Add(x1 + x1 + x1 + x1 == 0);
solver.Add(x3 + x2 + x1 + x3 == 0);
solver.Add(x7 + x6 + x6 + x2 == 2);
solver.Add(x9 + x3 + x1 + x2 == 1);
solver.Add(x0 + x0 + x0 + x0 == 4);
solver.Add(x2 + x2 + x2 + x2 == 0);
solver.Add(x3 + x3 + x3 + x3 == 0);
solver.Add(x5 + x5 + x5 + x5 == 0);
solver.Add(x8 + x1 + x9 + x3 == 3);
solver.Add(x8 + x0 + x9 + x6 == 5);
solver.Add(x7 + x7 + x7 + x7 == 0);
solver.Add(x9 + x9 + x9 + x9 == 4);
solver.Add(x7 + x7 + x5 + x6 == 1);
solver.Add(x6 + x8 + x5 + x5 == 3);
solver.Add(x9 + x8 + x8 + x1 == 5);
solver.Add(x5 + x5 + x3 + x1 == 0);
// The unknown
solver.Add(x2 + x5 + x8 + x1 == x);
}
else if (p == 2)
{
// Another representation of Problem 1
int[,] problem1 = { { 8, 8, 0, 9, 6 }, { 7, 1, 1, 1, 0 }, { 2, 1, 7, 2, 0 }, { 6, 6, 6, 6, 4 },
{ 1, 1, 1, 1, 0 }, { 3, 2, 1, 3, 0 }, { 7, 6, 6, 2, 2 }, { 9, 3, 1, 2, 1 },
{ 0, 0, 0, 0, 4 }, { 2, 2, 2, 2, 0 }, { 3, 3, 3, 3, 0 }, { 5, 5, 5, 5, 0 },
{ 8, 1, 9, 3, 3 }, { 8, 0, 9, 6, 5 }, { 7, 7, 7, 7, 0 }, { 9, 9, 9, 9, 4 },
{ 7, 7, 5, 6, 1 }, { 6, 8, 5, 5, 3 }, { 9, 8, 8, 1, 5 }, { 5, 5, 3, 1, 0 } };
for (int i = 0; i < problem1.GetLength(0); i++)
{
solver.Add((from j in Enumerable.Range(0, 4) select all[problem1[i, j]]).ToArray().Sum() ==
problem1[i, 4]);
}
solver.Add(all[2] + all[5] + all[8] + all[1] == x);
}
else if (p == 3)
{
// Problem 2
solver.Add(x8 + x8 + x0 + x9 == 6);
solver.Add(x7 + x6 + x6 + x2 == 2);
solver.Add(x9 + x3 + x1 + x2 == 1);
solver.Add(x8 + x1 + x9 + x3 == 3);
solver.Add(x8 + x0 + x9 + x6 == 5);
solver.Add(x7 + x7 + x5 + x6 == 1);
solver.Add(x6 + x8 + x5 + x5 == 3);
solver.Add(x9 + x8 + x8 + x1 == 5);
// The unknown
solver.Add(x2 + x5 + x8 + x1 == x);
}
else
{
// Another representation of Problem 2
int[,] problem2 = { { 8, 8, 0, 9, 6 }, { 7, 6, 6, 2, 2 }, { 9, 3, 1, 2, 1 }, { 8, 1, 9, 3, 3 },
{ 8, 0, 9, 6, 5 }, { 7, 7, 5, 6, 1 }, { 6, 8, 5, 5, 3 }, { 9, 8, 8, 1, 5 } };
for (int i = 0; i < problem2.GetLength(0); i++)
{
solver.Add((from j in Enumerable.Range(0, 4) select all[problem2[i, j]]).ToArray().Sum() ==
problem2[i, 4]);
}
solver.Add(all[2] + all[5] + all[8] + all[1] == x);
}
//
// Search
//
DecisionBuilder db = solver.MakePhase(all, Solver.INT_VAR_DEFAULT, Solver.INT_VALUE_DEFAULT);
solver.NewSearch(db);
while (solver.NextSolution())
{
Console.Write("x: {0} x0..x9: ", x.Value());
for (int i = 0; i < n; i++)
{
Console.Write(all[i].Value() + " ");
}
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)
{
for (int p = 1; p <= 4; p++)
{
Solve(p);
}
}
}