Forwards on Weibo (30)

BFS，题意比较难懂，是求离query L层的总共人数

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <map>
#include <vector>
#include <queue>

using namespace std;

const int N = 1005;

struct E
{
	int node;
};
vector<E> v[N];

int mark[N];

void add_edge(int a, int b)
{
	E tmp;
	tmp.node = b;

	v[a].push_back(tmp);
}

struct ANS
{
	int num;
	int lev;
};

void BFS(int x, int ll)
{
	queue<ANS> q;
	ANS tmp;
	tmp.lev = 0;
	tmp.num = x;
	q.push(tmp);
	mark[x] = 1;

	int level = 0;
	int ans = 0;
	while (!q.empty())
	{
		ANS top = q.front();

		int node = top.num;
		int lev = top.lev;
		if (lev >= ll) break;
		q.pop();

		for (int i = 0; i < v[node].size(); i++)
		{
			if (mark[v[node][i].node] == 0)
			{
				mark[v[node][i].node] = 1;

				tmp.lev = lev + 1;
				tmp.num = v[node][i].node;

				//printf("%d %d\n", tmp.num, tmp.lev);
				ans++;
				q.push(tmp);
			}
		}
	}

	printf("%d\n", ans);
}

int main()
{
	int n, ll;

	while (scanf("%d%d", &n, &ll) != EOF)
	{
		for (int i = 1; i <= n; i++)
		{
			int k, a;
			scanf("%d", &k);
			while (k--)
			{
				scanf("%d", &a);
				add_edge(a, i);
			}
		}
		int query_num, query;
		scanf("%d", &query_num);
		while (query_num--)
		{
			scanf("%d", &query);
			memset(mark, 0, sizeof(mark));
			BFS(query, ll);
		}
	}
	return 0;
}