Jungle Roads【北京大学】

题目链接

#include
#include
#include
#define N 2500
using namespace std;
//定义边的结构体  
struct edge{
	int u,v;
	int cost;
	bool operator < (const edge &b)const{
	return cost < b.cost;
	}
}E[N]; 
int father[105];
int findFather(int x){
	if(father[x] == x) return x;
	else{
		int tp = findFather(father[x]);
		father[x] = tp;
		return tp;
	}
}
int main(){
	int n;
	while(cin>>n){
		if(n==0) break;
		int num = 0;   //k表示与它相连的边 num用来记录边的条数
		char u,v; 
		for(int i = 0;i < (n-1);i++){
			int k;
			cin>>u>>k;
			for(int j = 0;j < k;j++){
			cin>>v>>E[num].cost;
				E[num].u = u - 'A' + 1; 
				E[num].v = v - 'A' + 1;
				num++;
			}	
		}
		sort(E,E+num);
		for(int i = 1;i <= n;i++){
			father[i] = i;
		}
		int ans = 0;
		for(int i=0;i<num;i++){
			int faU = findFather(E[i].u);
			int faV = findFather(E[i].v);
			if(faU != faV){
				father[faU] = faV;
			    ans += E[i].cost;
			}	   
		}
		cout<<ans<<endl;
	}
	return 0;
}