并查集还是不熟，还得练
#include<iostream>
#include<set>
#include<map>
#include<algorithm>
#include<vector>
#define int long long
const int N = 1e6;
using namespace std;
char* p1, * p2, buf[100000];
#define nc() (p1==p2 && (p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++)
int read()
{int x = 0, f = 1;char ch = nc();while (ch < 48 || ch>57){if (ch == '-')f = -1;ch = nc();}while (ch >= 48 && ch <= 57)x = x * 10 + ch - 48, ch = nc();return x * f;
}
int a[N];
int ans = 0;
int n, c;
int f[N];
int find(int x) {//查询并修改父节点if (f[x] == x)return x;f[x] = find(f[x]);return f[x];
}
void unionn(int x, int y) {f[y] = x;
}
signed main() {ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);int n, m, p;cin >> n >> m>>p;for (int i = 1; i <= n; i++)f[i] = i;for (int i = 1; i <= m; i++) {int p1, p2;cin >> p1 >> p2;int r1 = find(p1);int r2 = find(p2);if (r1 != r2)unionn(r1, r2);//合并两个点}for (int i = 1; i <= p; i++) {int p1, p2;cin >> p1 >> p2;if (find(p1) == find(p2))cout << "Yes" << endl;else cout << "No" << endl;}return 0;
}
