搬运jiangly鸽鸽的板子

#include <iostream>
#include <string>
#include <vector>
#include <numeric>struct DSU {std::vector<int> f, siz;DSU() {}DSU(int n) {init(n);}void init(int n) {f.resize(n);std::iota(f.begin(), f.end(), 0);siz.assign(n, 1);}int find(int x) {while (x != f[x]) {x = f[x] = f[f[x]];}return x;}bool same(int x, int y) {return find(x) == find(y);}bool merge(int x, int y) {x = find(x);y = find(y);if (x == y) {return false;}siz[x] += siz[y];f[y] = x;return true;}int size(int x) {return siz[find(x)];}
};int main() {std::cin.tie(nullptr)->sync_with_stdio(false);int n,m;std::cin >> n >> m;DSU dsu = DSU(n);while(m--){std::string op;int a,b;std::cin >> op;if(op=="C"){std::cin >> a >> b;if(!dsu.same(a,b)) dsu.merge(a,b);}else if(op=="Q1"){std::cin >> a >> b;std::cout << (dsu.same(a,b)?"Yes\n":"No\n");}else{std::cin >> a;std::cout << dsu.size(a) << '\n';}}return 0;
}