利用回溯法+贪心算法实现马踏棋盘功能。具体描述：有一M*N的棋盘，输入马所在的起始位置，输出马走过的全部路径。（马走过棋盘上每一个点）-The use of backtracking greedy algorithm+ horse riding board features. Specific descr iption: There is an M* N chessboard, enter the horse where the starting position, the output of