package sudoku.constraint;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import sudoku.structure.Sudoku;

public interface IConstraint extends Serializable {
	boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex);

	default List<Integer> getPossibleSymbols(final Sudoku s, int x, int y) {
		List<Integer> possibilities = new ArrayList<>();
		for (int i = 0; i < s.getSize(); i++) {
			if (canBePlaced(s, x, y, i)) {
				possibilities.add(i);
			}
		}
		return possibilities;
	}

}