1 #include<cstdio>
2 #include<iostream>
3 #include<queue>
4 #include<cstring>
5
6 using namespace std;
7
8 int ex, ey, sx, sy, step, g[10][10];
9
10 struct node{
11 int x, y, step;
12 };
13
14 int dir[8][2] = {{2, 1}, {1, 2}, {-1, 2}, {2, -1}, {-2, 1}, {1, -2}, {-1, -2}, {-2, -1}};
15 //方向
16 inline void bfs(){
17 memset(g, 0, sizeof(g));
18 queue<node> q;
19 node now, next;
20 now.x = sx;
21 now.y = sy;
22 now.step = 0;
23 g[now.x][now.y] = 1;
24 q.push(now);
25 while(!q.empty()){
26 now = q.front();
27 q.pop();
28 if(now.x == ex && now.y == ey){
29 step = now.step;
30 return;//找到终点
31 }
32 for(int i = 0; i < 8; i++){
33 next.x = now.x + dir[i][0];
34 next.y = now.y + dir[i][1];
35 if(next.x >= 1 && next.x <= 8 && next.y >= 1 && next.y <= 8 && !g[next.x][next.y]){
36 next.step = now.step + 1;
37 g[next.x][next.y] = 1;
38 q.push(next);
39 }
40 }
41 }
42 }
43
44
45 int main(){
46 char c1, c2;
47 int s, t;
48 while(~scanf("%c%d %c%d", &c1, &s, &c2, &t)){
49 getchar();
50 sx = c1 - 'a' + 1;
51 sy = s;
52 ex = c2 - 'a' + 1;
53 ey = t;//起终点
54 bfs();
55 printf("To get from %c%d to %c%d takes %d knight moves.\n", c1, s, c2, t, step);
56 }
57 return 0;
58 }
