package com.allen;

public class Knight {

public boolean travel(int startX,

int startY, int[][] board) {

// 对应骑士可以走的八个方向

int[] ktmove1 = {-2, -1, 1, 2, 2, 1, -1, -2};

int[] ktmove2 = {1, 2, 2, 1, -1, -2, -2, -1};

// 下一个出路的位置

int[] nexti = new int[board.length];

int[] nextj = new int[board.length];

// 记录出路的个数

int[] exists = new int[board.length];

int x = startX;

int y = startY;

board[x][y] = 1;

for(int m = 2; m <= Math.pow(board.length, 2); m++) {

for(int k = 0; k < board.length; k++) {

exists[k] = 0;

}

int count = 0;

// 试探八个方向

for(int k = 0; k < board.length; k++) {

int tmpi = x + ktmove1[k];

int tmpj = y + ktmove2[k];

// 如果是边界，不可以走

if(tmpi < 0 || tmpj < 0 ||

tmpi > 7 || tmpj > 7) {

continue;

}

// 如果这个方向可以走，记录下来

if(board[tmpi][tmpj] == 0) {

nexti[count] = tmpi;

nextj[count] = tmpj;

// 可走的方向加一个

count++;

}

}

int min = -1;

if(count == 0) {

return false;

}

else if(count == 1) {

min = 0;

}

else {

// 找出下个位置的出路数

for(int l = 0; l < count; l++) {

for(int k = 0; k < board.length; k++) {

int tmpi = nexti[l] + ktmove1[k];

int tmpj = nextj[l] + ktmove2[k];

if(tmpi < 0 || tmpj < 0 ||

tmpi > 7 || tmpj > 7) {

continue;

}

if(board[tmpi][tmpj] == 0)

exists[l]++;

}

}

int tmp = exists[0];

min = 0;

// 从可走的方向寻找最少出路的方向

for(int l = 1; l < count; l++) {

if(exists[l] < tmp) {

tmp = exists[l];

min = l;

}

}

}

// 走最少出路的方向

x = nexti[min];

y = nextj[min];

board[x][y] = m;

}

return true;

}

public static void main(String[] args) {

int[][] board = new int[8][8];

Knight knight = new Knight();

if(knight.travel(

Integer.parseInt(args[0]),

Integer.parseInt(args[1]), board)) {

System.out.println("走棋完成！");

}

else {

System.out.println("走棋失败！");

}

for(int i = 0; i < board.length; i++) {

for(int j = 0; j < board[0].length; j++) {

if(board[i][j] < 10) {

System.out.print(" " + board[i][j]);

}

else {

System.out.print(board[i][j]);

}

System.out.print(" ");

}

System.out.println();

}

}

}