该代码实现的的是可再生贪食蛇，具体规则如下：贪食蛇第一次碰墙后不会马上死掉，而是反向而行，第二次碰墙后会变短一节，第三次碰墙后地图中的中央会重新出现一条贪食蛇，蛇的长度与上一次“假死”的长度一样。-The code is implemented renewable Snake, specific rules are as follows: Snake hit the wall after the first will not immediately die, but reverse the line, hit the wall after the second section becomes shorter, Map of central reappears after the third hit the wall a snake, the length of the snake and the last "suspended animation" of the same length.