kuangbin 并查集 C - How Many Tables HDU - 1213

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<sstream>
#include<cmath>
#include<stack>
#include<map>
#include<cstdlib>
#include <vector>
#include<queue>
using namespace std;
const int INF = 0x3f3f3f3f;
const int maxn = 1e3+5;

int father[maxn];
void init(int n)
{
    for(int i=1;i<=n;i++)
        father[i] = i;
}
int find(int x)
{
    if(father[x] == x)
        return x;
    else
        return father[x] = find(father[x]);
}
void combine(int x,int y)
{
    x = find(x);
    y = find(y);
    if(x != y)
        father[x] = y;
}
int main()
{
   int t;
   scanf("%d",&t);
   while(t--)
   {
       int n,m;
       scanf("%d %d", &n,&m);
       init(n);
       for(int i=0;i<m;i++)
       {
           int a,b;
           scanf("%d%d",&a,&b);
           combine(a,b);
       }
       int res = 0;
       for(int i=1;i<=n;i++)
           if(i == find(i))
               res++;
       printf("%d\n",res);
   }
}