RandomPlayer.java

 
import java.util.*;

/**
 * A rando player for a Sokoban puzzle.
 * 
 * @author Dr Mark C. Sinclair
 * @version September 2021
 * 
 */
public class RandomPlayer implements Player {
    /**
     * Default constructor
     */
    public RandomPlayer() {
        rnd = new Random();
    }

    /**
     * Select a random direction from the vector of choices.
     * 
     * @param choices possible directions for the player to choose from
     * @return a random direction
     */
    @Override
    public Direction move(Vector<Direction> choices) {
        if (choices == null)
            throw new IllegalArgumentException("cannot have null choices");
        if (choices.isEmpty())
            throw new IllegalArgumentException("cannot have empty choices");
        int size = choices.size();
        int idx  = rnd.nextInt(size);
        return choices.get(idx);
    }

    private Random rnd = null;
}