hdu 1213 求连通分量（并查集模板题）

求连通分量

Sample Input
2 //T
5 3 //n m
1 2// u v
2 3
4 5

5 1
2 5

Sample Output
2
4

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <algorithm>
 # include <cmath>
 # include <queue>
 # define LL long long
 using namespace std ;
 
 const int MAXN=;
 int F[MAXN] ;
 int find(int x)//找x的祖先结点
 {
     if(F[x]==x) return x;
     return F[x]=find(F[x]);
 }
 void bing(int u,int v)
 {
     int t1=find(u);
     int t2=find(v);
     if(t1!=t2) //这两个点不在一个集合里
       F[t1]=t2; //合到一个集合里
 }
 
 int main()
 {
     //freopen("in.txt","r",stdin) ;
     int T ;
     scanf("%d" , &T) ;
     while(T--)
     {
         int n , m ;
         int i ;
         scanf("%d %d" , &n , &m) ;
         for (i =  ; i<= n ; i++)
            F[i] = i ;
         int u , v ;
         while(m--)
         {
             scanf("%d %d" , &u , &v) ;
             bing(u,v) ;
         }
         int res =  ;
         for (i =  ; i<= n ; i++)
             if (F[i] == i)
                res++ ;
         printf("%d\n" , res) ;
 
     }
 
     return ;
 }