用回溯法求解KnightTour问题

【KnightTour问题】在一个8×8的棋盘上，检验以某一位置作为出发点的棋子能否遍历一次棋盘上的所有棋格，且最后回到出发点。（备注：棋子每次只能沿东、南、西、北、东南、西南、东北、西北方向走一步！！)-Method with back issues KnightTour】 【KnightTour issues in a 8 × 8 chessboard, the examination for the position as the starting point of a piece of a chessboard can traverse all the chess grid, and the final return to the starting point. (Note: each piece can only be along the east, south, west, north, southeast, southwest, northeast, northwest direction step!!)