编写程序求解骑士巡游问题：在n行n列的棋盘上（如n=5），假设一位骑士（按象棋中“马走日”的行走法）从初始坐标位置(x1，y1)出发，要遍访（巡游）棋盘中的每一个位置一次。请编一个程序，为骑士求解巡游“路线图”（或告诉骑士，从某位置出发时，无法遍访整个棋盘 — 问题无解）。



当n=5时，意味着要在5行5列的棋盘的25个“点”处，按骑士行走规则，依次将1至25这25个“棋子”（数码）分别摆放到棋盘上（摆满25个位置则成功，否则失败问题无解）。

-Knight Parade programming to solve the problem: In the n-n chessboard (for example, n = 5), assuming a knight (in chess in the " horse to go on"　walk method) from the initial coordinates (x1, y1) starting , to be visited (cruise) position in each of the board once. Please compile a program to solve for the Knight Parade " road map"　(or tell the knight, starting from a position, you can not visited the board- problem has no solution.) When n = 5, meaning 5 rows 5 columns in the board' s 25 " points"　at, according to Knight walking rule, in turn 1 to 25 of these 25 " pieces"　(digital) were placed into the board ( 25 positions were filled with success, or failure problem has no solution.)