PAT 1076. Forward on Weibo (30)

#include<iostream>
#include<queue>
#include<vector>
using namespace std;
struct users{
	int size;
	vector<int> follow;
}usr[1001];
bool visit[1001] = { false };
queue<int> que;
int itg_to_level[1001] = { 0 };

int n, l;
int k;
int cnt = 0;
void query(int id){
	for (int i = 1; i <= n; i++){
		if (visit[i])		continue;
		for (int j = 0; j < usr[i].size; j++){
			if (id == usr[i].follow[j]){
				que.push(i);
				visit[i] = true; 
				itg_to_level[i] = itg_to_level[id] + 1;
				cnt++;
				break;
			}
		}
	}
}
int main(){
	cin >> n >> l;
	for (int i = 1; i <= n; i++){
		int tmp_size; cin >> tmp_size;
		usr[i].size = tmp_size;
		usr[i].follow.resize(tmp_size);
		for (int j = 0; j < tmp_size; j++)
			cin >> usr[i].follow[j];
	}
	cin >> k;
	for (int i = 0; i < k; i++){
		cnt = 0;
		for (int k = 1; k <= n; k++){
			visit[k] = false;
			itg_to_level[k] = 0;
		}
		int id; cin >> id;
		itg_to_level[id] = 1;
		visit[id] = true;
		que.push(id); 
		while (!que.empty() && itg_to_level[que.front()] <= l){
			int q = que.front();
			query(q);
			que.pop();
		}
		while (!que.empty())	que.pop();
		cout << cnt << endl;
	}
}