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

123 lines
3.7 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 JustForgotten
{
/**
*
* Just forgotten puzzle (Enigma 1517) in Google CP Solver.
*
* From http://www.f1compiler.com/samples/Enigma 201517.f1.html
* """
* Enigma 1517 Bob Walker, New Scientist magazine, October 25, 2008.
*
* Joe was furious when he forgot one of his bank account numbers.
* He remembered that it had all the digits 0 to 9 in some order,
* so he tried the following four sets without success:
*
* 9 4 6 2 1 5 7 8 3 0
* 8 6 0 4 3 9 1 2 5 7
* 1 6 4 0 2 9 7 8 5 3
* 6 8 2 4 3 1 9 0 7 5
*
* When Joe finally remembered his account number, he realised that
* in each set just four of the digits were in their correct position
* and that, if one knew that, it was possible to work out his
* account number. What was it?
* """
*
* Also see http://www.hakank.org/google_or_tools/just_forgotten.py
*
*/
private static void Solve()
{
Solver solver = new Solver("JustForgotten");
int rows = 4;
int cols = 10;
// The four tries
int[,] a = { { 9, 4, 6, 2, 1, 5, 7, 8, 3, 0 },
{ 8, 6, 0, 4, 3, 9, 1, 2, 5, 7 },
{ 1, 6, 4, 0, 2, 9, 7, 8, 5, 3 },
{ 6, 8, 2, 4, 3, 1, 9, 0, 7, 5 } };
//
// Decision variables
//
IntVar[] x = solver.MakeIntVarArray(cols, 0, 9, "x");
//
// Constraints
//
solver.Add(x.AllDifferent());
for (int r = 0; r < rows; r++)
{
solver.Add((from c in Enumerable.Range(0, cols) select x[c] == a[r, c]).ToArray().Sum() == 4);
}
//
// Search
//
DecisionBuilder db = solver.MakePhase(x, Solver.INT_VAR_DEFAULT, Solver.INT_VALUE_DEFAULT);
solver.NewSearch(db);
while (solver.NextSolution())
{
Console.WriteLine("Account number:");
for (int j = 0; j < cols; j++)
{
Console.Write(x[j].Value() + " ");
}
Console.WriteLine("\n");
Console.WriteLine("The four tries, where '!' represents a correct digit:");
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
String c = " ";
if (a[i, j] == x[j].Value())
{
c = "!";
}
Console.Write("{0}{1} ", a[i, j], c);
}
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();
}
}