ortools-clone/examples/contrib/survo_puzzle.cs

//
// 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.Text.RegularExpressions;
using Google.OrTools.ConstraintSolver;

public class SurvoPuzzle {
  //
  // default problem
  //
  static int default_r = 3;
  static int default_c = 4;
  static int[] default_rowsums = {30, 18, 30};
  static int[] default_colsums = {27, 16, 10, 25};
  static int[, ] default_game = {{0, 6, 0, 0}, {8, 0, 0, 0}, {0, 0, 3, 0}};

  // for the actual problem
  static int r;
  static int c;
  static int[] rowsums;
  static int[] colsums;
  static int[, ] game;

  /**
   *
   * Solves the Survo puzzle.
   * See http://www.hakank.org/or-tools/survo_puzzle.py
   *
   */
  private static void Solve() {
    Solver solver = new Solver("SurvoPuzzle");

    //
    // data
    //
    Console.WriteLine("Problem:");
    for (int i = 0; i < r; i++) {
      for (int j = 0; j < c; j++) {
        Console.Write(game[i, j] + " ");
      }
      Console.WriteLine();
    }
    Console.WriteLine();

    //
    // Decision variables
    //
    IntVar[, ] x = solver.MakeIntVarMatrix(r, c, 1, r * c, "x");
    IntVar[] x_flat = x.Flatten();

    //
    // Constraints
    //
    for (int i = 0; i < r; i++) {
      for (int j = 0; j < c; j++) {
        if (game[i, j] > 0) {
          solver.Add(x[i, j] == game[i, j]);
        }
      }
    }

    solver.Add(x_flat.AllDifferent());

    //
    // calculate rowsums and colsums
    //
    for (int i = 0; i < r; i++) {
      IntVar[] row = new IntVar[c];
      for (int j = 0; j < c; j++) {
        row[j] = x[i, j];
      }
      solver.Add(row.Sum() == rowsums[i]);
    }

    for (int j = 0; j < c; j++) {
      IntVar[] col = new IntVar[r];
      for (int i = 0; i < r; i++) {
        col[i] = x[i, j];
      }
      solver.Add(col.Sum() == colsums[j]);
    }

    //
    // Search
    //
    DecisionBuilder db = solver.MakePhase(x_flat, Solver.INT_VAR_SIMPLE,
                                          Solver.ASSIGN_MIN_VALUE);

    solver.NewSearch(db);

    int sol = 0;
    while (solver.NextSolution()) {
      sol++;
      Console.WriteLine("Solution #{0} ", sol + " ");
      for (int i = 0; i < r; i++) {
        for (int j = 0; j < c; j++) {
          Console.Write("{0} ", x [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();
  }

  /**
   *
   * readFile()
   *
   * Reads a Survo puzzle in the following format
   * r
   * c
   * rowsums
   * olsums
   * data
   * ...
   *
   * Example:
   * 3
   * 4
   * 30,18,30
   * 27,16,10,25
   * 0,6,0,0
   * 8,0,0,0
   * 0,0,3,0
   *
   */
  private static void readFile(String file) {
    Console.WriteLine("readFile(" + file + ")");

    TextReader inr = new StreamReader(file);

    r = Convert.ToInt32(inr.ReadLine());
    c = Convert.ToInt32(inr.ReadLine());
    rowsums = new int[r];
    colsums = new int[c];
    Console.WriteLine("r: " + r + " c: " + c);

    String[] rowsums_str = Regex.Split(inr.ReadLine(), ",\\s*");
    String[] colsums_str = Regex.Split(inr.ReadLine(), ",\\s*");
    Console.WriteLine("rowsums:");
    for (int i = 0; i < r; i++) {
      Console.Write(rowsums_str[i] + " ");
      rowsums[i] = Convert.ToInt32(rowsums_str[i]);
    }
    Console.WriteLine("\ncolsums:");
    for (int j = 0; j < c; j++) {
      Console.Write(colsums_str[j] + " ");
      colsums[j] = Convert.ToInt32(colsums_str[j]);
    }
    Console.WriteLine();

    // init the game matrix and read data from file
    game = new int[r, c];
    String str;
    int line_count = 0;
    while ((str = inr.ReadLine()) != null && str.Length > 0) {
      str = str.Trim();

      // ignore comments
      // starting with either # or %
      if (str.StartsWith("#") || str.StartsWith("%")) {
        continue;
      }

      String[] this_row = Regex.Split(str, ",\\s*");
      for (int j = 0; j < this_row.Length; j++) {
        game[line_count, j] = Convert.ToInt32(this_row[j]);
      }

      line_count++;

    }  // end while

    inr.Close();

  }  // end readFile

  public static void Main(String[] args) {
    String file = "";
    if (args.Length > 0) {
      file = args[0];
      readFile(file);
    } else {
      r = default_r;
      c = default_c;
      game = default_game;
      rowsums = default_rowsums;
      colsums = default_colsums;
    }

    Solve();
  }
}