// // 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(); } }