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\n",ans);

    }

    return 0;

}