/*本人先后编了两次，第二次进行了改进。改进的思想主要是注意到棋盘上每一点的下一可到达点的个数

（下称为权值）不同，对于可到达点较少（权值小）的点应该先跳上去，这样后来跳的点可跳的方向就比

较多，回溯的现象就比较少，这样就可以大幅度提高速度*/-/ * I have compiled twice, the second time for improvements. Improved thinking is that every point on the chessboard of the next point can be reached by the number (hereinafter referred to as the right value), For less accessible spots (small weights) should be the first point and jumped out of the way and then jump to the point of jumping on the direction of more, Looking back on the phenomenon of relatively small, we can significantly improve the speed * /