HDU 1301 Jungle Roads

题解：最小生成树…………

#include <cstdio>
#include <algorithm>
using namespace std;
struct node{int a,b,l;}seg[900];
int f[27],m,n,a,b; char c;
int sf(int x){return f[x]==x?x:f[x]=sf(f[x]);}
bool cmp(node a,node b){return a.l<b.l;}
void scanc(int &x){
    while(c=getchar(),c<'A'||c>'Z');x=c-'A';
}
void scan(int &x){
    while(c=getchar(),c<'0'||c>'9');x=c-'0';
    while(c=getchar(),c>='0'&&c<='9')x=x*10+c-'0';
}
int main(){
    while(~scanf("%d",&n)){
        if(n==0)break;int ans=0,t=0,cnt=n-1;
        for(int i=0;i<=n;i++)f[i]=i;
        for(int i=0;i<n-1;i++){
            scanc(a);scan(m);
            for(int j=0;j<m;j++)seg[t].a=a,scanc(seg[t].b),scan(seg[t++].l);
        }
        sort(seg,seg+t,cmp); int i=-1;
        while(cnt){
            int q=sf(seg[++i].a),w=sf(seg[i].b);
            if(q!=w)cnt--,f[q]=w,ans+=seg[i].l;
        }
        printf("%d
",ans);
    }
    return 0;
}