1 #include <iostream>
 2 #include <cstdio>
 3 #include <queue>
 4 #include <cstring>
 5 using namespace std;
 6 int dx[]={1,-1,1,-1,2,-2,2,-2};
 7 int dy[]={2,-2,-2,2,1,-1,-1,1};
 8 int vis[9][9];
 9 struct point
10 {
11     int x;
12     int y;
13     int t;
14 }st,tem,nex;
15 int sx,sy,ex,ey,tim;
16 char a,b,c,d;
17 void bfs()
18 {
19     queue<point> s;
20     st.x=sx,st.y=sy;
21     st.t=0;
22     s.push(st);
23     memset(vis,0,sizeof(vis));
24     while(!s.empty())
25     {
26         tem=s.front();
27         s.pop();
28 
29         if(tem.x==ex&&tem.y==ey)
30         {
31             tim=tem.t;
32             return;
33         }
34         if(vis[tem.x][tem.y]||tem.x<=0||tem.y<=0||tem.x>8||tem.y>8)
35             continue;
36         vis[tem.x][tem.y]=1;
37         for(int i=0;i<8;i++)
38         {
39             int nx=tem.x+dx[i];
40             int ny=tem.y+dy[i];
41             int nt=tem.t+1;
42             nex.x=nx,nex.y=ny,nex.t=nt;
43             s.push(nex);
44         }
45     }
46 }
47 int main()
48 {
49     freopen("in.txt","r",stdin);
50     while(scanf("%c%c %c%c",&a,&b,&c,&d)!=EOF)
51     {
52         getchar();
53         tim=0;
54         sy=a-‘a‘+1,sx=b-‘0‘;
55         ey=c-‘a‘+1,ex=d-‘0‘;
56         bfs();
57         printf("To get from %c%c to %c%c takes %d knight moves.\n",a,b,c,d,tim);
58     }
59 }