POJ - 1251 Jungle Roads(最小生成树)

 1 #include <iostream>
 2 #include <algorithm>
 3 using namespace std;
 4 
 5 struct TnT{
 6     int x1;
 7     int x2;
 8     int val;
 9 }T[1111];
10 
11 int Father[30];
12 char arr[27]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
13 
14 int find(int x){return x==Father[x]?x:Father[x]=find(Father[x]);}
15 
16 void Union(int x,int y){
17     int fx=find(x),fy=find(y);
18     if(fx!=fy) Father[fx]=fy;
19 }
20 
21 bool cmp(TnT a,TnT b){
22     return a.val<b.val;
23 }
24 
25 int renum(char m){
26     for(int i=0;i<26;i++){
27         if(m==arr[i])
28         return i+1;
29     }
30 }
31 
32 int main(){
33     int n,l,r,cnt;
34     char m;
35     while(cin>>n&&n!=0){
36         int t=0,sum=0;
37         for(int i=1;i<=n;i++) Father[i]=i;
38         for(int i=1;i<n;i++){
39             cin>>m>>cnt;
40             l=renum(m);
41             for(int i=0;i<cnt;i++){
42                 cin>>m>>T[t].val;
43                 r=renum(m);
44                 T[t].x1=l,T[t].x2=r;
45                 t++;
46             }
47         }
48         sort(T,T+t,cmp);
49         for(int i=0;i<t;i++){
50             if(find(T[i].x1)!=find(T[i].x2)){
51                 Union(T[i].x1,T[i].x2);
52                 sum+=T[i].val;
53             }
54         }
55         cout<<sum<<endl;
56     }
57     return 0;
58 }