poj1251--Kruskal

/*
* poj1251-- Kruskal
* date 2014/7/15
* state AC
*/

#include <iostream>
#include <algorithm>
#include <fstream>
#include <cstdio>
#include <cstring>

using namespace std;

int const MAXN=30+100;
int u[MAXN];
int v[MAXN];
int w[MAXN+50];

int p[MAXN];
int r[MAXN];

int cmp(const int i,const int j)
{
return w[i]<w[j];
}

int unionFindSet(int x)
{
return p[x]==x?x:p[x]=unionFindSet(p[x]);
}

int Kruskal(int n,int m)
{
int ans=0;

//memset(p,0,sizeof(p));
//memset(r,0,sizeof(r));

for(int i=0;i<n;i++)
p[i]=i;
for(int i=0;i<m;i++)
r[i]=i;

//mem
sort(r,r+m,cmp);
for(int i=0;i<m;i++)
{
int e=r[i];
int x=unionFindSet(u[e]);
int y=unionFindSet(v[e]);
if(x!=y)
{
ans+=w[e];
p[x]=y;
}
}
return ans;
}
int main()
{
//cout << "Hello world!" << endl;
//freopen("input.txt","r",stdin);
char a[2],b[2];
int c;
int m;
int n;
int edgeNum;
while(scanf("%d",&n))
{
if(n==0)break;

memset(u,0,sizeof(u));
memset(v,0,sizeof(v));
memset(w,0,sizeof(w));

edgeNum=0;
for(int i=0;i<n-1;i++)
{
scanf("%s%d",a,&m);
for(int j=0;j<m;j++)
{
scanf("%s%d",b,&c);
u[edgeNum]=a[0]-'A';
v[edgeNum]=b[0]-'A';
w[edgeNum]=c;
edgeNum++;
}
}
//
/*cout<<"edgeNumber: "<<edgeNum<<endl;
for(int k=0;k<edgeNum;k++)
cout<<u[k]<<" "<<v[k]<<" "<<w[k]<<"    ";
cout<<"---"<<endl;
*/
cout<<Kruskal(n,edgeNum)<<endl;
}
return 0;
}