题目描述 https://www.luogu.org/problemnew/show/P1529
把字母转换成数字后，求离Z点最近的奶牛，近似模板题。

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int mp[60][60],p; 
int main() 
{ 
   scanf("%d",&p);
   memset(mp,0x7f/3,sizeof(mp));
   for(int i=1;i<=55;i++) mp[i][i]=0;
   for(int i=1;i<=p;i++)
   {
   	  char a,b; int x,y,z;
   	  cin>>a>>b>>z;
   	  if(a>='A'&&a<='Z') x=a-'A'+1+26;
   	  else x=a-'a'+1;
   	  if(b>='A'&&b<='Z') y=b-'A'+1+26;
   	  else y=b-'a'+1;
   	  mp[x][y]=mp[y][x]=min(mp[x][y],z);
   }
   for(int k=1;k<=52;k++)
     for(int i=1;i<=52;i++)
       for(int j=1;j<=52;j++)
         mp[i][j]=min(mp[i][j],mp[i][k]+mp[k][j]);
   int minn=1e9,z;
   for(int i=27;i<=51;i++)
     if(mp[i][52]<minn)  
       minn=mp[i][52],z=i;
   z='A'+z-27;
   cout<<(char)z<<" "<<minn;
 	
  return 0;	
}