题解

#include <iostream>
#include <vector>
using namespace std;

const int MAXN = 5e5 + 10;
int fa[MAXN], sz[MAXN];

void init(int n) {
for (int i = 1; i <= n; ++i) {
fa[i] = i;
sz[i] = 1;
}
}

int find(int x) {
if (fa[x] != x) fa[x] = find(fa[x]);
return fa[x];
}

void unite(int x, int y) {
x = find(x), y = find(y);
if (x == y) return;
if (sz[x] < sz[y]) swap(x, y);
fa[y] = x;
sz[x] += sz[y];
}

int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);

int n, m;
cin >> n >> m;
init(n);

while (m--) {
    int k;
    cin >> k;
    if (k <= 1) { 
        for (int i = 0; i < k; ++i) {
            int tmp; cin >> tmp;
        }
        continue;
    }
    vector<int> g(k);
    for (int i = 0; i < k; ++i) cin >> g[i];
    int root = g[0];
    for (int i = 1; i < k; ++i) {
        unite(root, g[i]);
    }
}

for (int i = 1; i <= n; ++i) {
    cout << sz[find(i)] << " ";
}
return 0;

}