hdu 1213 求连通分量（并查集模板题）

 1 # include <iostream>
 2 # include <cstdio>
 3 # include <cstring>
 4 # include <algorithm>
 5 # include <cmath>
 6 # include <queue>
 7 # define LL long long
 8 using namespace std ;
 9 
10 const int MAXN=1010;
11 int F[MAXN] ;
12 int find(int x) //找x的祖先结点
13 {
14     while(x!=F[x])
15         x=F[x];
16      return x;
17 }
18 void bing(int u,int v)
19 {
20     int t1=find(u);
21     int t2=find(v);
22     if(t1!=t2) //这两个点不在一个集合里
23       F[t1]=t2; //合到一个集合里
24 }
25 
26 
27 int main()
28 {
29     //freopen("in.txt","r",stdin) ;
30     int T ;
31     scanf("%d" , &T) ;
32     while(T--)
33     {
34         int n , m ;
35         int i ;
36         scanf("%d %d" , &n , &m) ;
37         for (i = 1 ; i<= n ; i++)
38            F[i] = i ;
39         int u , v ;
40         while(m--)
41         {
42             scanf("%d %d" , &u , &v) ;
43             bing(u,v) ;
44         }
45         int res = 0 ;
46         for (i = 1 ; i<= n ; i++)
47             if (F[i] == i)
48                res++ ;
49         printf("%d\n" , res) ;
50 
51     }
52 
53     return 0;
54 }