题目

#include<bits/stdc++.h>
#include<unordered_map>
using namespace std;
long long n, ls, i, k, k2;
bool book[100001];
vector<long long> v[1000001];
unordered_map<int, bool> m[3001];
long long a[1001];
void DFS(int d) {
	m[i][d] = 1;
	for (auto i : v[d]) {
		DFS(i);
	}
}
int main() {
	cin >> n;
	for (int i = 1; i < n; i++) {
		m[0][i] = 1;
		cin >> ls;
		v[ls].push_back(i);
	}
	for (i = 1; i < n; i++) {
		DFS(i);
	}
	cin >> k;
	while (k--) {
		cin >> k2;
		for (int i = 1; i <= k2; i++) {
			cin >> a[i];
		}
		for (int i = n - 1; i >= 0; i--) {
			bool f = 1;
			for (int j = 1; j <= k2; j++) {
				if (!m[i][a[j]]) {
					f = 0;
					break;
				}
			}
			if (f) {
				cout << i << "\n";
				break;
			}
		}
	}
	return 0;
}