50 lines
1.0 KiB
Java
50 lines
1.0 KiB
Java
package sudoku.solver;
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import java.util.List;
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import java.util.concurrent.CancellationException;
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import sudoku.structure.Cell;
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import sudoku.structure.MultiDoku;
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public class BacktrackingSolver implements Solver {
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/**
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* Résout le MultiDoku passé en paramètre, avec backtracking.
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*
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* @param doku MultiDoku, MultiDoku à résoudre.
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* @return boolean, valant true si le MultiDoku est résolu, false sinon.
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*/
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@Override
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public 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.isSolved()) {
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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 = cellToFill.getPossibleSymbols();
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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 (this.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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