石头剪刀布的php非循环写法

<?php

/**
 * Rock Paper Scissors
 * by inuxor
 */

function rps() {
	$rps = array("石头", "剪刀", "布");
	$keys = array_keys($rps);
	shuffle($keys);
	$computer = $keys[0];

	echo "请输入: 石头 剪刀 布\n";
	$keyin = trim(fgets(STDIN));
	$person = array_search($keyin, $rps);
	if($person === false){
		echo "输入错误！！\n";
		rps();

	}else{
		echo "电脑出的是:" . $rps[$computer] . "\n";

		$action = $computer - $person;
		if($action == 0){
			echo "平局\n";
		}else if($action == -2 || $action == 1){
			echo "你赢\n";
		}else{
			echo "电脑赢\n";
		}
		echo "再来一次?(y/n)\n";
		$yorn = trim(fgets(STDIN));
		if($yorn == 'y'){
			rps();
		}else if($yorn == 'n'){
			echo "Bye\n";
		}else{
			echo "全当是再来一次了，再来！\n";
			rps();
		}
	}


}

echo "开始猜拳游戏\n";
rps();