题目：https://pintia.cn/problem-sets/994805342720868352/problems/994805372601090048

常规BFS和DFS都可以，这里为了再熟悉一下BFS的写法，用了BFS
一开始从0开始求最值了，改成从1开始就过了

代码

  1. #include<vector>
  2. #include<algorithm>
  3. #include<iostream>
  4. #include<queue>
  5. using namespace std;
  7. const int maxn = 110;
  8. struct Node{
  9.     int depth;
  10.     vector<int> child;
  11. }node[maxn];
  13. int n, m;
  14. int depth_table[110] = {0};
  16. void BFS(){
  17.     queue<int> q;
  18.     q.push(1);
  19.     node[1].depth = 1;
  20.     while(!q.empty()){
  21.         int top = q.front();
  22.         q.pop();
  23.         for(int i = 0; i < node[top].child.size(); i++){
  24.             int child = node[top].child[i];
  25.             node[child].depth = node[top].depth + 1;
  26.             q.push(child);
  27.         }
  28.     }
  29. }
  31. void caculate(){
  32.     int max_index = 1;
  33.     for(int i = 1; i < maxn; i++) depth_table[node[i].depth]++;
  34.     for(int i = 1; i < maxn; i++){
  35.         if(depth_table[i] > depth_table[max_index]){
  36.             max_index = i;
  37.         }
  38.     }
  39.     printf("%d %d", depth_table[max_index], max_index);
  40. }
  42. int main(){
  43.     scanf("%d%d", &n, &m);
  44.     int id, child_num, child_temp;
  45.     for(int i = 0; i < m; i++){
  46.         scanf("%d%d", &id, &child_num);
  47.         for(int j = 0; j < child_num; j++){
  48.             scanf("%d", &child_temp);
  49.             node[id].child.push_back(child_temp);
  50.         }
  51.     }
  52.     BFS();
  53.     caculate();
  54.     return 0;
  55. }