POJ 1251

 1 #include<iostream>
 2 #include<vector>
 3 #include<algorithm>
 4 #define MAX_N 150
 5 using namespace std;
 6 int pre[MAX_N];
 7 int n;
 8 char c[MAX_N],c1[MAX_N];
 9 int finds(int x)
10 {
11     return x==pre[x]?x:finds(pre[x]);
12 }
13 void unions(int x, int y)
14 {
15     int find_x=finds(x);
16     int find_y=finds(y);
17     if(find_x==find_y)
18         return;
19     pre[find_x]=find_y;
20 }
21 bool Judge(int x, int y)
22 {
23     return finds(x)==finds(y);
24 }
25 struct Pit
26 {
27     int l,r,w;
28 } p;
29 vector<Pit> V;
30 bool cmp(Pit p1,Pit p2)
31 {
32     return p1.w<p2.w;
33 }
34 int main()
35 {
36     while(cin>>n)
37     {
38         V.clear();
39         if(n==0) break;
40         for(int i=0; i<n; i++)
41         {
42             pre[i]=i;
43         }
44         for(int i=0; i<n-1; i++)
45         {
46             int a;
47             cin>>c>>a;
48             for(int i=0; i<a; i++)
49             {
50                 int b;
51                 cin>>c1>>b;
52                 p.l=c[0]-‘A‘;
53                 p.r=c1[0]-‘A‘;
54                 p.w=b;
55                 V.push_back(p);
56             }
57         }
58         int ans=0;
59         sort(V.begin(),V.end(),cmp);
60         for(int i=0; i<V.size(); i++)
61         {
62             if(Judge(V[i].l,V[i].r))
63                 continue;
64             ans+=V[i].w;
65             unions(V[i].l,V[i].r);
66         }
67         cout<<ans<<endl;
68     }
69 
70 }