| 1 | /* |
| 2 | * Copyright (c) 2005 The PseudoQ Project. |
| 3 | * |
| 4 | * This file is part of PseudoQ. |
| 5 | * |
| 6 | * PseudoQ is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU Lesser General Public License as published by |
| 8 | * the Free Software Foundation; either version 2.1 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * PseudoQ is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public License |
| 17 | * along with PseudoQ; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | package net.sourceforge.pseudoq.solver; |
| 22 | |
| 23 | import java.util.HashSet; |
| 24 | import java.util.LinkedList; |
| 25 | import java.util.List; |
| 26 | |
| 27 | import net.sourceforge.pseudoq.model.Coordinate; |
| 28 | import net.sourceforge.pseudoq.model.Region; |
| 29 | |
| 30 | /** |
| 31 | * Counts the number of possible values that can be placed in a given cell. |
| 32 | * @author <a href="http://sourceforge.net/users/stevensa">Andrew Stevens</a> |
| 33 | */ |
| 34 | public class CellPossibilitiesCounter implements Counter { |
| 35 | private List<Integer> possibilities; |
| 36 | private Coordinate coord; |
| 37 | private Region region; |
| 38 | private int digits; |
| 39 | |
| 40 | /** Creates a new instance of CellPossibilitiesCounter */ |
| 41 | public CellPossibilitiesCounter(Coordinate coord, int digits, Region region) { |
| 42 | if (coord == null) { |
| 43 | throw new IllegalArgumentException("Can't create counter for null coordinates"); |
| 44 | } |
| 45 | if (region == null) { |
| 46 | throw new IllegalArgumentException("Can't create counter for null region"); |
| 47 | } |
| 48 | if (digits <= 0) { |
| 49 | throw new IllegalArgumentException("Can't create counter with no digits"); |
| 50 | } |
| 51 | |
| 52 | this.coord = coord; |
| 53 | this.region = region; |
| 54 | this.digits = digits; |
| 55 | reset(); |
| 56 | } |
| 57 | |
| 58 | public void place(Coordinate coord, int value) { |
| 59 | assert (this.coord != null); |
| 60 | assert (region != null); |
| 61 | assert (possibilities != null); |
| 62 | |
| 63 | if (this.coord.equals(coord)) { |
| 64 | possibilities.clear(); |
| 65 | possibilities.add(Integer.valueOf(value)); |
| 66 | } else if (region.contains(coord)) { |
| 67 | possibilities.remove(Integer.valueOf(value)); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | public int getCount() { |
| 72 | assert (possibilities != null); |
| 73 | |
| 74 | return possibilities.size(); |
| 75 | } |
| 76 | |
| 77 | public void reset() { |
| 78 | assert (digits > 0); |
| 79 | |
| 80 | possibilities = new LinkedList<Integer>(); |
| 81 | for (int i = 1; i <= digits; i++) { |
| 82 | possibilities.add(Integer.valueOf(i)); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Getter for property possibilities. |
| 88 | * @return Value of property possibilities. |
| 89 | */ |
| 90 | public List<Integer> getPossibilities() { |
| 91 | return this.possibilities; |
| 92 | } |
| 93 | |
| 94 | } |