洛谷

#include<bits/stdc++.h>
using namespace std;
const int N = 1e6 + 7;
int fa[N];
int n, m;
int find(int x) {
    if(fa[x] == x) return x;
    return fa[x] = find(fa[x]);
}
void unionset(int x, int y) {
    fa[find(x)] = find(y);
}
int main() {
    cin >> n >> m;
    for(int i = 1; i <= n; i++) {
        fa[i] = i;
    }
    while(m--) {
        int x, a, b;
        cin >> x >> a >> b;
        if(x == 1) {
            unionset(a, b);
        }
        else{
            a = find(a), b = find(b);
            if(a == b) cout << "Y\n";
            else cout << "N\n";
        }
    }
    return 0;
}

查找x的父节点
int find(int x) {
    if(fa[x] == x) return x;
    return fa[x] = find(fa[x]);//路径压缩
}

合并
void unionset(int x, int y) {
    fa[find(x)] = find(y);
}