zebra4j.PuzzleGenerator Maven / Gradle / Ivy

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/*-
 * #%L
 * zebra4j
 * %%
 * Copyright (C) 2020 Marin Nozhchev
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * .
 * #L%
 */
package zebra4j;

import java.util.Collection;
import java.util.Iterator;
import java.util.Random;
import java.util.Set;
import java.util.stream.Stream;

import javax.annotation.concurrent.ThreadSafe;

import zebra4j.fact.Fact;

/**
 * A generator for {@link Puzzle}
 * 
 * 
 * You can use the same generator to create multiple different puzzles by
 * calling the {@link #generate()} method multiple times. All generated puzzles
 * will have the same attributes and solution but will have different facts
 * (clues).
 */
@ThreadSafe
public class PuzzleGenerator extends AbstractPuzzleGenerator {

	/**
	 * Generate a new random puzzle using defaults
	 * 
	 * @param numPeople number of people in the puzzle
	 * @return
	 */
	public static Puzzle randomPuzzle(int numPeople) {
		PuzzleGenerator generator = new PuzzleGenerator(new SolutionGenerator(numPeople).generate(),
				DEFAULT_FACT_TYPES);
		return generator.generate();
	}

	public PuzzleGenerator(PuzzleSolution solution, Set factTypes) {
		this(new Random(), solution, factTypes);
	}

	public PuzzleGenerator(Random rnd, PuzzleSolution solution, Set factTypes) {
		super(rnd, solution, factTypes);
	}

	@Override
	protected Puzzle toPuzzle(Collection facts) {
		return new Puzzle(solution.getAttributeSets(), facts);
	}

	@Override
	protected int countSolutions(Puzzle puzzle) {
		return new PuzzleSolver(puzzle, getChocoSettings()).solve().size();
	}

	@Override
	protected boolean uniqueSolution(Puzzle puzzle) {
		Iterator iter = solveToStream(puzzle).iterator();
		if (!iter.hasNext()) {
			return false;
		}
		PuzzleSolution first = iter.next();
		while (iter.hasNext()) {
			if (!first.equals(iter.next())) {
				return false;
			}
		}
		return true;
	}

	private Stream solveToStream(Puzzle puzzle) {
		return new PuzzleSolver(puzzle, getChocoSettings()).solveToStream();
	}

}