1076 Forwards on Weibo (30 分)

1076 Forwards on Weibo (30 分)

思路有空更新

#include <iostream>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
vector<int> v[1050];
int n, l, k, x, m, vis[1050];
int bfs(int x){
    
	int level = 0, ret = 0;
	queue<int> q;
	q.push(x);
	vis[x] = 1;
	while(!q.empty() && level < l){
    
		int size = q.size();
		for(int i = 0; i < size; ++i){
    
			int a = q.front();
			for(int j = 0; j < v[a].size(); ++j){
    
				if(!vis[v[a][j]]){
    
					q.push(v[a][j]);
					vis[v[a][j]] = 1;
					ret++;
				}
			}
			q.pop();
		}
		level++;
	}
	return ret;
} 
int main() {
    
	cin >> n >> l;
	for(int i = 1; i <= n; ++i) {
    
		cin >> m;
		while(m--) {
    
			cin >> x;
			v[x].push_back(i);
		}
	}
	cin >> k;
	while(k--) {
    
		memset(vis, 0, sizeof vis);
		cin >> x;
		cout << bfs(x) << endl;
	}
}