> /*******************************************************************
> **author:LiangHong
> **date:2008.6.11
> **describe:pku2243
> *******************************************************************/
> 
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> int used[50][50], x2, y2;
> char a[3], b[3];
> int d[8][2]={{-1,-2},{-1,2},{-2,1},{-2,-1},{2,1},{2,-1},{1,2},{1,-2}};
> typedef struct {
>     int x;
>     int y;
>     int moves;
> }point;
> point queue[10000];
> void bfs(int x1,int y1);
> 
> int main(void)
> {
>     int  i, j, x1, y1, t;
> 
>     while (scanf("%s%s", a, b) != EOF) {
>         for (i = 1; i <= 8; i++)
>             for (j = 'a'-'a'; j <= 'h'-'a'; j++)
>                 used[i][j] = 1;
>         memset(queue, 0, sizeof(point)*1000);
>         x2 = b[0]-'a';
>         y2 = b[1]-'1';
>         x1 = a[0]-'a';
>         y1 = a[1]-'1';
>         if (x1 > x2) {
>             t = x1;
>             x1 = x2;
>             x2 = t;
>             t = y1;
>             y1 = y2;
>             y2 = t;
>         }
>         bfs(x1, y1);
>     }
>     return 0;
> 
> }
> 
> void bfs(int x1,int y1)
> {
>     int tx, ty, k, cx, cy, i;
>     point temp;
>     int head = 0, tail = 1;
>     queue[0].x = x1;
>     queue[0].y = y1;
>     queue[0].moves = 0;
>     i = 0;
>     while(head < tail)
> 	{
> 		cx=queue[head].x;
> 		cy=queue[head].y;
> 		head++;
> 		if (cx == x2 && cy == y2) {
>             break;
> 		}
> 		for(k = 0; k < 8; k++)
> 		{
> 			tx = cx + d[k][0];
> 			ty = cy + d[k][1];
> 			temp.x = tx;
> 			temp.y = ty;
> 			temp.moves = queue[i].moves+1;
> 			if(tx >= 0 && tx <= 8 && ty >= 'a'-'a' && ty <= 'h'-'a' && used[tx][ty])
> 			{
> 				queue[tail].x = temp.x;
> 				queue[tail].y = temp.y;
> 				queue[tail].moves = temp.moves;
> 				tail++;
> 				used[tx][ty] = 0;
> 			}
> 		}
> 		i++;
> 	}
> 	printf("To get from %s to %s takes %d knight moves.\n", a, b, queue[i].moves);
> }


先感謝你一下看了你的我才改正并ac了，我是因為數組沒有清零，估計你的也是吧