1 // 2 // Copyright 2012 Hakan Kjellerstrand 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 16 using System; 17 using System.Collections; 18 using System.IO; 19 using System.Linq; 20 using System.Text.RegularExpressions; 21 using Google.OrTools.ConstraintSolver; 22 23 public class JustForgotten 24 { 25 /** 26 * 27 * Just forgotten puzzle (Enigma 1517) in Google CP Solver. 28 * 29 * From http://www.f1compiler.com/samples/Enigma 201517.f1.html 30 * """ 31 * Enigma 1517 Bob Walker, New Scientist magazine, October 25, 2008. 32 * 33 * Joe was furious when he forgot one of his bank account numbers. 34 * He remembered that it had all the digits 0 to 9 in some order, 35 * so he tried the following four sets without success: 36 * 37 * 9 4 6 2 1 5 7 8 3 0 38 * 8 6 0 4 3 9 1 2 5 7 39 * 1 6 4 0 2 9 7 8 5 3 40 * 6 8 2 4 3 1 9 0 7 5 41 * 42 * When Joe finally remembered his account number, he realised that 43 * in each set just four of the digits were in their correct position 44 * and that, if one knew that, it was possible to work out his 45 * account number. What was it? 46 * """ 47 * 48 * Also see http://www.hakank.org/google_or_tools/just_forgotten.py 49 * 50 */ Solve()51 private static void Solve() 52 { 53 Solver solver = new Solver("JustForgotten"); 54 55 int rows = 4; 56 int cols = 10; 57 58 // The four tries 59 int[,] a = { { 9, 4, 6, 2, 1, 5, 7, 8, 3, 0 }, 60 { 8, 6, 0, 4, 3, 9, 1, 2, 5, 7 }, 61 { 1, 6, 4, 0, 2, 9, 7, 8, 5, 3 }, 62 { 6, 8, 2, 4, 3, 1, 9, 0, 7, 5 } }; 63 64 // 65 // Decision variables 66 // 67 IntVar[] x = solver.MakeIntVarArray(cols, 0, 9, "x"); 68 69 // 70 // Constraints 71 // 72 solver.Add(x.AllDifferent()); 73 for (int r = 0; r < rows; r++) 74 { 75 solver.Add((from c in Enumerable.Range(0, cols) select x[c] == a[r, c]).ToArray().Sum() == 4); 76 } 77 78 // 79 // Search 80 // 81 DecisionBuilder db = solver.MakePhase(x, Solver.INT_VAR_DEFAULT, Solver.INT_VALUE_DEFAULT); 82 83 solver.NewSearch(db); 84 85 while (solver.NextSolution()) 86 { 87 Console.WriteLine("Account number:"); 88 for (int j = 0; j < cols; j++) 89 { 90 Console.Write(x[j].Value() + " "); 91 } 92 Console.WriteLine("\n"); 93 Console.WriteLine("The four tries, where '!' represents a correct digit:"); 94 for (int i = 0; i < rows; i++) 95 { 96 for (int j = 0; j < cols; j++) 97 { 98 String c = " "; 99 if (a[i, j] == x[j].Value()) 100 { 101 c = "!"; 102 } 103 Console.Write("{0}{1} ", a[i, j], c); 104 } 105 Console.WriteLine(); 106 } 107 Console.WriteLine(); 108 } 109 110 Console.WriteLine("\nSolutions: {0}", solver.Solutions()); 111 Console.WriteLine("WallTime: {0}ms", solver.WallTime()); 112 Console.WriteLine("Failures: {0}", solver.Failures()); 113 Console.WriteLine("Branches: {0} ", solver.Branches()); 114 115 solver.EndSearch(); 116 } 117 Main(String[] args)118 public static void Main(String[] args) 119 { 120 Solve(); 121 } 122 } 123