并查集模版题

#include <iostream>

using namespace std;
const int N = 20010;
int p[N], n, m, q, u, v;

int find(int x) {
  return p[x] ^ x ? p[x] = find(p[x]) : x;
}

int main(void) {
  for (int i = 0; i < N; ++i) p[i] = i;
  scanf("%d %d", &n, &m);
  while (m--) {
    scanf("%d %d", &u, &v);
    p[find(u)] = p[find(v)];
  }
  scanf("%d", &q);
  while (q--) {
    scanf("%d %d", &u, &v);
    puts(find(u) == find(v) ? "Yes" : "No");
  }
  return 0;
}