【NOIP模板】 并查集

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;int n, m, p, r1, r2, fa[50010];int find(int x) {    if(fa[x] == x) return x;    return fa[x] = find(fa[x]);}int main() {    scanf("%d %d %d", &n, &m, &p);    for(int i = 1; i <= n; i ++) fa[i] = i;    for(int i = 1; i <= m; i ++) {        scanf("%d %d", &r1, &r2);        int p1 = find(r1);        int p2 = find(r2);        fa[p1] = p2;    }    for(int i = 1; i <= p; i ++) {        scanf("%d %d", &r1, &r2);        int p1 = find(r1);        int p2 = find(r2);        if(p1 == p2) printf("Yes\n");        else printf("No\n");    }    return 0;}