说明：  老鼠走迷宫是递回求解的基本题型，我们在二维阵列中使用2表示迷宫墙壁，使用1来表示老鼠的行走路径，试以程式求出由入口至出口的路径
(Mouse Maze is a recursive solution of the basic kinds of questions, we use 2 dimensional array that maze walls, mice with a walking path to that and try to find the program path from the inlet to the outlet)