C :

#include<stdio.h>
#include<ctype.h>
#include<string.h>
#include<stdlib.h>

int c[27];
typedef struct
{
  int s,e,cost;
}ROAD;

int cmp(const void* pa,const void* pb)
{
   return (*(ROAD*)pa).cost>(*(ROAD*)pb).cost;
}

int find(int n)
{
   int tmp;
   if(c[n]==-1) return n;
   else 
   {
      tmp=find(c[n]);
	  c[n]=tmp;
	  return tmp;
   }
}

int main()
{
    int i,j,k,n,m,s,sum,a,b;
    char str[2],str1[2];
	ROAD r[76];
	while(scanf("%d",&n)!=EOF&&n!=0)
	{
		memset(c,-1,sizeof(int)*27);
		for(m=0,i=0;i<n-1;i++)
		{
		  scanf("%s%d",str,&k);
		  for(j=0;j<k;j++)
		  {
		    r[m].s=str[0]-'A';
            scanf("%s%d",str1,&r[m].cost);
			r[m].e=str1[0]-'A';
			m++;
		  }
		}
        qsort(r,m,sizeof(ROAD),cmp);
		for(i=0,sum=k=0;i<m&&k!=n-1;i++)
		{
		  a=find(r[i].s);
		  b=find(r[i].e);
		  if(a!=b)
		  {
		    c[a]=b;
			k++;
			sum+=r[i].cost;
		  }
		
		}
		printf("%d\n",sum);  
	}
	return 0;
}

C++ :

 #include <iostream>
 #include <stdio.h>
 #include <algorithm>
 #include <string.h>
 using namespace std;
 
 struct node{
     int x,y,len;
 }road[5050];
 int pre[30];
 
 int find(int x)
 {
     if(pre[x]!=x)
         pre[x]=find(pre[x]);
     return pre[x];
 }
 
 int Union(int a,int b)
 {
     int x,y;
     x=find(a);
     y=find(b);
     if(x==y) return 1;
     else 
     {
         pre[y]=x;
         return 0;
     }
 }
 
 bool cmp(node a,node b)
 {
     return a.len<b.len;
 }
 
 int main()
 {    
     int n,m,i,j,p,q;
     char a,b;
     while(scanf("%d",&n)==1)
     {
         if(n==0) break;
         int k=0;
         for(i=1;i<n;i++)
         {
             cin>>a>>m;
             for(j=1;j<=m;j++)
             {
                 road[k].x=a-'A'+1;
                 cin>>b>>q;
                 road[k].y=b-'A'+1;
                 road[k].len=q;
                 k++;
             }
             pre[i]=i;
         }
         pre[i]=i;
         sort(road,road+k,cmp);
         int ans=0;
         for(i=0;i<k;i++)
         {
             if(Union(road[i].x,road[i].y)==0)
                 ans+=road[i].len;
         }
         printf("%d\n",ans);
     }
     return 0;
 }