hdu5441 并查集+克鲁斯卡尔算法

#include <iostream>
#include <algorithm>
#include <string.h>
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
const int maxn=20005;
typedef long long LL;
struct edg{
   int a,b,d;
   edg(int ca=0,int cb=0,int cd=0)
   {
        a=ca; b=cb; d=cd;
   }
   bool operator <(const edg &rhs)const{
      return d<rhs.d;
   }
}E[100005];
struct query{
   LL id,d;
   query(LL cid=0, LL cd=0 ){
       id=cid; d=cd;
   }
   bool operator <(const query &rhs)const {
       return d<rhs.d;
   }
}Q[5005];
LL S[maxn];
LL num[maxn];
int fa[maxn];
int fin(int a)
{
     return fa[a]=(fa[a]==a)?a:fin(fa[a]);
}
LL ans[5005];
int main()
{

    int cas;
    scanf("%d",&cas);
    for(int cc=1; cc<=cas; cc++)
        {
             int n,m,q;
             scanf("%d%d%d",&n,&m,&q);
             for(int i=0; i<m; i++)scanf("%d%d%d",&E[i].a,&E[i].b,&E[i].d);
             for(int i=0; i<=n; i++){fa[i]=i;S[i]=0;num[i]=1;}
             for(int i=0; i<q; i++) {scanf("%I64d",&Q[i].d);Q[i].id=i; ans[i]=0;}
             sort(E,E+m);
             sort(Q,Q+q);
             int loc=0;
             LL D=0;
             for(int i=0; i<q; i++)
                {
                    while(loc<m&&E[loc].d<=Q[i].d){
                        int a=E[loc].a,b=E[loc].b;
                        a=fin(a);
                        b=fin(b);
                        if(a==b){ loc++; continue; }
                        D=D-S[a]-S[b];
                        fa[b]=a;
                        num[a]+=num[b];
                        S[a]=1LL*num[a]*(num[a]-1);
                        D=D+S[a];
                        loc++;
                    }
                   ans[Q[i].id]=D;
                }
                for(int i=0; i<q; i++)
                    printf("%I64d\n",ans[i]);
        }
    return 0;
}