PAT (Advanced) 1076. Forwards on Weibo (30)

#include <iostream>#include <cstring>using namespace std;const int MAX = 1000;bool edge[MAX][MAX];bool visited[MAX];int queue[MAX];int BFS(int start, int n, int level){int res = 0;int front = 0, rear = 1, level_last;queue[front] = start;visited[start] = true;while (front < rear){level_last = rear;level--;while (front < level_last){int i = queue[front++];for (int j = 0; j < n; j++){if (!visited[j] && edge[i][j]){visited[j] = true;res++;queue[rear++] = j;}}}if (level == 0)break;}return res;}int main(){int N, L;cin >> N >> L;int M, s;for (int i = 0; i < N; i++){cin >> M;for (int j = 0; j < M; j++){cin >> s;edge[s - 1][i] = true;}}int K;int start;int sum;cin >> K;for (int i = 0; i < K; i++){memset(visited, false, sizeof(visited));cin >> start;cout << BFS(start - 1, N, L) << endl;}}