uva 439

/*************************************************************************
     File Name: uva439.cpp
     Author: yubo
     Mail: [e-mail] 
     Created Time: 2014/5/18 23:15:55
reference:http://blog.sina.com.cn/s/blog_6730a3aa0100vkzd.html
相似于中国象棋中的马的走法，可是这道题改来改去最终自己做出来了
input:
e2 e4
a1 b2
b2 c3
a1 h8
a1 h7
h8 a1
b1 c3
f6 f6
 ************************************************************************/

#include<iostream>
#include<cstring>
#include<queue>
#include<cstdio>
using namespace std;
int dir[8][2]={
  {2,1},{2,-1},{1,2},{1,-2},{-1,2},{-1,-2},{-2,1},{-2,-1},
};
typedef struct{
  int x,y;
  int times;

}SE;
int x1,y1,x2,y2;//
int judge1(int i,int j)
{
  if(i>=0&&i<8&&j>=0&&j<8)
    return 1;
  else
    return 0;

}
int vis[8][8];
char command[2][5];//记录命令
int ans;
void bfs(int x,int y)
{
  queue<SE> q;
  SE q0,q1,q2;
  q0.x=x;
  q0.y=y;
  q0.times=0;
  vis[x][y]=1;
  q.push(q0);
  while(!q.empty()){
    q1=q.front();
    q.pop();
    for(int i=0;i<8;i++){
      int temp1=q1.x+dir[i][0];
      int temp2=q1.y+dir[i][1];
      if(judge1(temp1,temp2)&&!vis[temp1][temp2]){
        if(temp1==x2&&temp2==y2){
          ans=q1.times+1;
          return ;
        }
        q2.x=temp1;
        q2.y=temp2;
        q2.times=q1.times+1;
        vis[temp1][temp2]=1;
        q.push(q2);
      }
    }


  }


}
int main()
{
//  freopen("in.txt","r",stdin);
  while(cin>>command[0]>>command[1]){
    memset(vis,0,sizeof(vis));
    y1=command[0][0]-'a';
    x1=command[0][1]-'1';
    y2=command[1][0]-'a';
    x2=command[1][1]-'1';
    ans=0;
//    printf("%d %d %d %d\n",x1,y1,x2,y2);
//    printf("%s\n",command[0]);
    bfs(x1,y1);
    cout<<"To get from "<<command[0]<<" to "<<command[1]<<" takes "<<ans<<" knight moves."<<endl;
  }
}