PAT| 1076 Forwards on Weibo(图的广度优先遍历)

代码

#include 
#include 
#include 
using namespace std;
int n, l, m, k;
struct node {
    int id, layer;
};
vector<vector<int>> v;
int bfs(node tnode) {
    bool inq[1010] = {false};
    queue<node> q;
    q.push(tnode);
    inq[tnode.id] = true;
    int cnt = 0;
    while(!q.empty()) {
        node top = q.front();
        q.pop();
        int topid = top.id;
        for(int i = 0; i < v[topid].size(); i++) {
            int nextid = v[topid][i];
            if(inq[nextid] == false && top.layer < l) {
                node next = {nextid, top.layer + 1};
                q.push(next);
                inq[next.id] = true;
                cnt++;
            }
        }
    }
    return cnt;
}
 
int main() {
    scanf("%d %d", &n, &l);
    v.resize(n + 1);
    for(int i = 1; i <= n; i++) {
        scanf("%d", &m);
        for(int j = 0; j < m; j++) {
            int temp;
            scanf("%d", &temp);
            v[temp].push_back(i);
        }
    }
    scanf("%d", &k);
    int tid;
    for(int i = 0; i < k; i++) {
        scanf("%d", &tid);
        node tnode = {tid, 0};
        printf("%d\n", bfs(tnode));
    }
    return 0;
}