enum版本石头剪刀布

package test;

public enum Outcome{
WIN,LOSE,DRAW
}
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package test;

import java.util.Random;

import static test.Outcome.*;

interface Item {
	Outcome compete(Item it);

	Outcome eval(Paper p);

	Outcome eval(Scissors s);

	Outcome eval(Rock r);
}

class Paper implements Item {

	@Override
	public Outcome compete(Item it) {
		// TODO Auto-generated method stub
		return it.eval(this);
	}

	@Override
	public Outcome eval(Paper p) {
		// TODO Auto-generated method stub
		return DRAW;
	}

	@Override
	public Outcome eval(Scissors s) {
		// TODO Auto-generated method stub
		return WIN;
	}

	@Override
	public Outcome eval(Rock r) {
		// TODO Auto-generated method stub
		return LOSE;
	}

	public String toString() {
		return "Paper";

	}

}

class Scissors implements Item {

	@Override
	public Outcome compete(Item it) {
		// TODO Auto-generated method stub
		return it.eval(this);
	}

	@Override
	public Outcome eval(Paper p) {
		// TODO Auto-generated method stub
		return LOSE;
	}

	@Override
	public Outcome eval(Scissors s) {
		// TODO Auto-generated method stub
		return DRAW;
	}

	@Override
	public Outcome eval(Rock r) {
		// TODO Auto-generated method stub
		return WIN;
	}

	public String toString() {
		return "Scissors";

	}

}

class Rock implements Item {

	@Override
	public Outcome compete(Item it) {
		// TODO Auto-generated method stub
		return it.eval(this);
	}

	@Override
	public Outcome eval(Paper p) {
		// TODO Auto-generated method stub
		return WIN;
	}

	@Override
	public Outcome eval(Scissors s) {
		// TODO Auto-generated method stub
		return LOSE;
	}

	@Override
	public Outcome eval(Rock r) {
		// TODO Auto-generated method stub
		return DRAW;
	}

	public String toString() {
		return "Rock";

	}

}

public class RoShamBo1 {
	static final int SIZE = 20;
	private static Random rand = new Random(47);

	public static Item newItem() {
		switch (rand.nextInt(3)) {
		default:
		case 0:
			return new Scissors();
		case 1:
			return new Paper();
		case 2:
			return new Rock();
		}

	}

	public static void match(Item a, Item b) {
		System.out.println(a + " VS " + b + ":" + a.compete(b));
	}

	public static void main(String[] args) {
		for (int i = 0; i < SIZE; i++)
			match(newItem(), newItem());
	}
}