并查集

#include 
using namespace std;
#define LL long long
const int N = 1e4 + 10;
LL n, m, z, x, y;
vector  fa(N);
LL find(LL x){
	if (fa[x] == x) return x;
	return fa[x] = find(fa[x]);
}
void join(LL a, LL b){
	fa[find(b)] = find(a);
}
void solve(){
	cin >> n >> m;
	for (int i = 1; i <= n; i++)
		fa[i] = i;
	for (int i = 1; i <= m; i++){
		scanf("%lld%lld%lld", &z, &x, &y);
		if (z == 1)
			join(x, y);
		else
			if (find(x) == find(y))
				cout << "Y\n";
			else 
				cout << "N\n";
	}
}
int main(){
	solve();
	return 0;
}

模板：https://www.luogu.com.cn/problem/P3367