HDU 4750 Count The Pairs(并查集）

题目链接

没有发现那个点，无奈。

 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <queue>
 #include <algorithm>
 using namespace std;
 #define LL __int64
 int o[],rank[];
 struct node
 {
     int u,v,w;
 } edge[];
 int n,m;
 int que[];
 LL ans[];
 bool cmp(node a,node b)
 {
     return a.w < b.w;
 }
 int find(int x)
 {
     int r,t;
     r = x;
     while(x != o[x])
         x = o[x];
     while(r != x)
     {
         t = o[r];
         o[r] = x;
         r = t;
     }
     return x;
 }
 void merge(int x,int y)
 {
     x = find(x);
     y = find(y);
     if(x != y)
     {
         o[x] = y;
         rank[y] += rank[x];
     }
 }
 int bin(int x)
 {
     int str,end,mid;
     str = ;
     end = m-;
     if(x > que[end])
         return m;
     while(str < end)
     {
         mid = (str+end)/;
         if(que[mid] < x)
             str = mid + ;
         else
             end = mid;
     }
     return str;
 }
 int main()
 {
     int i,u,v,t;
     LL sum;
     while(scanf("%d%d",&n,&m)!=EOF)
     {
         for(i = ;i < n;i ++)
         {
             rank[i] = ;
             o[i] = i;
         }
         for(i = ; i < m; i ++)
         {
             scanf("%d%d%d",&edge[i].u,&edge[i].v,&edge[i].w);
             que[i] = edge[i].w;
             ans[i] = ;
         }
         sort(que,que+m);
         sort(edge,edge+m,cmp);
         sum = ;
         for(i = ; i < m; i ++)
         {
             u = find(edge[i].u);
             v = find(edge[i].v);
             if(u != v)
             {
                 ans[i] = (LL)rank[u] * rank[v]*;
                 sum += (LL)rank[u] * rank[v]*;
                 merge(u,v);
             }
         }
         for(i = ;i < m;i ++)
         ans[i] = ans[i] + ans[i-];
         scanf("%d",&t);
         for(i = ; i < t; i ++)
         {
             scanf("%d",&u);
             v = bin(u);
             if(v == )
                 printf("%I64d\n",sum);
             else
                 printf("%I64d\n",sum-ans[v-]);
         }
     }
     return ;
 }