hdu 1301 Jungle Roads

#include<iostream>
#include<vector>
#include<cmath>
#include<cstdio>
#define inf 1<<30
#define maxn 30
using namespace std;
int n;
vector<int>mapp[maxn];
int vaule[maxn][maxn];
int visit[maxn];
void prim()
{
int d[maxn];
fill(d,d+maxn,inf);
fill(visit,visit+maxn,0);
int re=0;
d[0]=0;
while(1)
{
int v=-1;
for(int i=0;i<n;i++)
{
if(!visit[i]&&(v==-1||d[i]<d[v])) v=i;
}
if(v==-1) break;
re+=d[v];
visit[v]=1;
for(int i=0;i<mapp[v].size();i++)
{
int x=mapp[v][i];
d[x]=min(d[x],vaule[v][x]);
}
}
cout<<re<<endl;
}
int main()
{
while(cin>>n&&n)
{
char a,b;
int m,x,z;
for(int i=0;i<maxn;i++) mapp[i].clear();
for(int i=0;i<n-1;i++)
{
cin>>a>>m;
for(int i=0;i<m;i++)
{
cin>>b>>z;
int x=a-'A',y=b-'A';
mapp[x].push_back(y);
mapp[y].push_back(x);
vaule[x][y]=z;
vaule[y][x]=z;
}
}
prim();
}
return 0;
}