hdu 1213 并查集

并查集基本题。

#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<string>
#include<map>
#include<set>
#include<algorithm>
#include<vector>
#include<queue>
#include<stack>
#include<sstream>
#define LL long long
#define OJ_DEBUG 0
#define READ_FILE 0
using namespace std;
const int NN_MAX = 1000+10;
const int MM_MAX = 100010;
const int INF = 0x3fffffff;
/**********************************************************/
int p[NN_MAX];
/**********************************************************/
int min_2 (int x,int y) {return x<y?x:y;}
int max_2 (int x,int y) {return x>y?x:y;}
void swap (int& a, int& b){a^=b;b^=a;a^=b;}
int find (int i){return i==p[i]?i:p[i]=find (p[i]);}
void merge (int i,int j){
  int x=find (i);
  int y=find (j);
  if (x!=y)
	p[y]=x;
}
/**********************************************************/
int main()
{
  if (READ_FILE) freopen ("in.txt","r",stdin);
  int tt,n,m;
  scanf ("%d",&tt);
  while (tt--)
  {
	scanf ("%d %d",&n,&m);
	int a,b;
	for (int i=0;i<=n;i++) p[i]=i;
	for (int i=0;i<m;i++){
	  scanf ("%d %d",&a,&b);
	  merge (a,b);
	}
	int cnt=0;
	for (int i=1;i<=n;i++)
	  if (i==find (i))
		cnt++;
	printf ("%d\n",cnt);
  }
  return 0;
}