119 lines
3.5 KiB
Java
119 lines
3.5 KiB
Java
package sudoku.solver;
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import sudoku.io.SudokuPrinter;
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import sudoku.structure.MultiDoku;
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import sudoku.structure.Cell;
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import sudoku.structure.Sudoku;
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import java.util.List;
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import java.util.Random;
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import java.util.concurrent.CancellationException;
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import java.util.logging.Level;
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import java.util.logging.Logger;
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public class Solver {
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private static final Logger logger = Logger.getLogger("SolverLogger");
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/**
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* Résout le multidoku passé en paramètre si c'est possible.
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* En testant toutes les possibilités, de manière aléatoire, avec un algorithme
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* de backtracking.
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*
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* @param doku Multidoku, à résoudre
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* @param rand Random, pour tester aléatoirement les symboles
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* @return boolean, true s'il est résolu ou false s'il ne l'est pas.
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*/
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public static boolean solveRandom(MultiDoku doku, Random rand) {
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if (Thread.interrupted())
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throw new CancellationException("User wants to stop the solver");
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Sudoku sudoku = doku.getSubGrid(0);
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logger.log(Level.INFO,
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'\n' + SudokuPrinter.toStringRectangleSudoku(sudoku,
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sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getBlockWidth(),
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sudoku.getBlockWidth() == 0 ? sudoku.getSize() : sudoku.getSize() / sudoku.getBlockWidth()));
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if (doku.isValid()) {
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return true;
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}
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Cell cellToFill = doku.getFirstEmptyCell();
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if (cellToFill == null) {
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return false;
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}
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List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
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while (!possibleSymbols.isEmpty()) {
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int nextPossibleSymbolIndex = rand.nextInt(possibleSymbols.size());
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int nextSymbol = possibleSymbols.get(nextPossibleSymbolIndex);
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cellToFill.setSymbolIndex(nextSymbol);
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if (Solver.solveRandom(doku, rand)) {
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return true;
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}
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cellToFill.setSymbolIndex(Cell.NOSYMBOL);
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possibleSymbols.remove(nextPossibleSymbolIndex);
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}
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return false;
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}
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public static int countSolution(MultiDoku doku) {
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int result = 0;
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if (doku.isValid()) {
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return 1;
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}
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Cell cellToFill = doku.getFirstEmptyCell();
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if (cellToFill == null) {
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return 0;
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}
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List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
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for (int symbol : possibleSymbols) {
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cellToFill.setSymbolIndex(symbol);
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if (Solver.solve(doku)) {
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result++;
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}
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cellToFill.setSymbolIndex(Cell.NOSYMBOL);
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}
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return result;
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}
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public static boolean solve(MultiDoku doku) {
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if (Thread.interrupted())
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throw new CancellationException("User wants to stop the solver");
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if (doku.isValid()) {
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return true;
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}
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Cell cellToFill = doku.getFirstEmptyCell();
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if (cellToFill == null) {
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return false;
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}
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List<Integer> possibleSymbols = doku.getPossibleSymbolsOfCell(cellToFill);
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if (possibleSymbols.isEmpty()) {
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return false;
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}
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for (int symbol : possibleSymbols) {
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cellToFill.setSymbolIndex(symbol);
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if (Solver.solve(doku)) {
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return true;
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} else {
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cellToFill.setSymbolIndex(Cell.NOSYMBOL);
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}
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}
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return false;
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}
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}
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