图论——并查集

/*
	并查集模板
		by：mfcheer
*/

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <set>
#include <map>  

using namespace std;
#define N 100010

int n, m;
int fa[N];

int findd(int x)
{
	if (fa[x] == -1)
		return x;
	else
		return fa[x] = findd(fa[x]);
}

void un(int x, int y)
{
	int fx = findd(x);
	int fy = findd(y);
	if (fx == fy)
		return;
	fa[fx] = fy;
}

int main()
{
	memset(fa, -1, sizeof(fa));
	while (cin >> n >> m)
	{
		un(n,m);
	}
	return 0;
}