1076. Forwards on Weibo 解析

注意题意输入粉丝的时候，第i行是第i个关注了谁，而不是他的粉丝。

在遍历的时候也是只转发第一次，所以要一个isVis数组去标记一下。

#include 
#include 
#include 
#include 
#include 

#define MAX 1010

using namespace std;

int n, l;
struct Node {
	int level;
	vector  follow;
	Node() { level = 1; }
};
Node list[MAX];
vector  s;
bool isVis[MAX];

void LevelOrder(int u) {
	queue  q;
	q.push(u);
	isVis[u] = true;
	list[u].level = 1;
	int topLevel = list[u].level;
	int NowLevel = topLevel;

	while (!q.empty()) {
		int top = q.front();
		q.pop();

		NowLevel = list[top].level;

		if (NowLevel - topLevel < l) {
			for (int i = 0; i < list[top].follow.size(); i++) {
				int v = list[top].follow[i];
				if (!isVis[v]) {
					list[v].level = NowLevel + 1;
					q.push(v);
					isVis[v] = true;
					s.push_back(v);
				}
			}
		}
		
	}
}




int main() {
	cin >> n >> l;

	int co, t;
	for (int i = 1; i <= n; i++) {
		cin >> co;
		for (int j = 0; j < co; j++) {
			cin >> t;
			list[t].follow.push_back(i);
		}
	}

	int m;
	cin >> m;
	for (int i = 0; i < m; i++) {
		cin >> t;
		memset(isVis, false, sizeof(isVis));
		s.clear();
		LevelOrder(t);
		cout << s.size() << endl;
	}

	return 0;
}