HDU1213

http://acm.split.hdu.edu.cn/showproblem.php?pid=1213

 #include<stdio.h>
 #include<algorithm>
 #include<iostream>
 #include<string.h>
 using namespace std;
 const int maxn=;
 int fa[maxn];
 int fin(int x)
 {
     return fa[x]==x?fa[x]:fa[x]=fin(fa[x]);
 }
 int unin(int x,int y){
 return fa[fin(y)]=fin(x);
 }
 int main()
 {
     int t,a,b;
     int m,n;
     cin>>t;
     while(t--){
      cin>>m>>n;
      for(int i=;i<=m;i++){
         fa[i]=i;
      }
      for(int i=;i<n;i++){
         scanf("%d%d",&a,&b);
         if(fin(a)!=fin(b)){
             unin(a,b);
         }
      }

      int temp=;
      for(int i=;i<=m;i++){
         if(fa[i]==i){
             temp++;
         }
      }
      cout<<temp<<endl;
 getchar();
     }
 }