【经典算法问题】马的遍历【回溯】

/*
马的遍历 回溯
在N*M的棋盘中的一点（x，y）开始遍历棋盘所有点
2014-4-8 20:10:48
*/
#include <stdio.h>
#define max 1000

struct Node{
int x, y;
}moveXY[8] = {{1, 2}, {1, -2}, {-1, 2}, {-1, -2},
{2, -1}, {2, 1}, {-2, 1}, {-2, -1}};

bool hasAccess[max][max];
Node store[max];
int n, m, id;

bool checkBound(int x, int y){
if(x < 1 || y < 1 || x > n || y > m) return 0;
return 1;
}

void print(){
for(int i = 1; i <= id; ++i){
if(i % 4 == 0) printf("\n");
printf("(%d, %d) ", store[i].x, store[i].y);
}
printf("\n\n");
}

void backTrack(Node k){
if(id == n * m){
print();
return;
}
Node temp;
for(int i = 0; i < 8; ++i){
if(checkBound(k.x + moveXY[i].x, k.y + moveXY[i].y) &&
!hasAccess[k.x + moveXY[i].x][k.y + moveXY[i].y]){
hasAccess[k.x + moveXY[i].x][k.y + moveXY[i].y] = 1;
temp.x = k.x + moveXY[i].x;
temp.y = k.y + moveXY[i].y;
store[++id] = temp;
backTrack(temp);
--id;
hasAccess[k.x + moveXY[i].x][k.y + moveXY[i].y] = 0;
}
}
}

int main(){
int x, y;
scanf("%d%d", &n, &m);
scanf("%d%d", &x, &y);
Node temp;
temp.x = x; temp.y = y;
store[++id] = temp;
hasAccess[x][y] = 1;
backTrack(temp);
return 0;
}