POJ1611 The Suspects ——并查集

​​​​​​POJ1611
 

题意：

有n个人，编号0-n-1，给出m个集合，问一共有多少个人和0号在一个集合。

思路：

直接并查集即可

// Decline is inevitable,
// Romance will last forever.
// POJ1611
//#include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <cstring>
#include <string>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <deque>
#include <vector>
using namespace std;
#define mst(a, x) memset(a, x, sizeof(a))
#define INF 0x3f3f3f3f
#define mp make_pair
#define pii pair<int,int>
#define fi first
#define se second
#define ll long long
//#define int long long
const int maxn = 3e4 + 10;
const int maxm = 25;
const int P = 1e9 + 7;
int fa[maxn];
int n, m;
int find(int x) {
    if(x == fa[x]) return x;
    return fa[x] = find(fa[x]);
}
void merge(int x, int y) {
    x = find(x);
    y = find(y);
    if(x != y)
        fa[x] = y;
}
void solve() {
    while(scanf("%d%d", &n, &m) && (n || m)) {
        for(int i = 0; i <= n; i++)
            fa[i] = i;
        for(int i = 1; i <= m; i++) {
            int k, x;
            scanf("%d%d", &k, &x);
            k--;
            while(k--) {
                int y;
                scanf("%d", &y);
                merge(x, y);
            }
        
        }
        int a = find(0);
        int cnt = 0;
        for(int i = 0; i < n; i++)
            if(find(i) == a) cnt++;
        printf("%d\n", cnt);
    }
}
signed main() {
//    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
//    int T; scanf("%d", &T); while(T--)
//    int T; cin >> T; while(T--)
    solve();
    return 0;
}

标签：Suspects,POJ1611,int,查集,long,fa,include,find,define
来源： https://blog.csdn.net/m0_59273843/article/details/120576885