蛇每增加一节延时减少1000毫秒 如果蛇头碰到食物，不运行下面语句 蛇的后一节的坐标等于前一节的坐标-Snake for each additional 1 millisecond delay to reduce if the snakeheads 1000 encounter of food, do not run the following statement after a snake is equal to the coordinates of the coordinates of th