拼图

代码说明：

  拼图游戏小程序，可以选择三种不同游戏难度，通过点击图片交换方格位置，记录移动次数，尽可能少步骤地完成。(Puzzle game small program, you can choose three different game difficulty, by clicking on the picture exchange box position, record the number of moves, as few steps as possible to complete.)