1004 Counting Leaves

大致题意就是给出一棵树，求出每一层叶子节点个数。

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

const int maxn = 200;
vector<int> node[maxn];
int hashtable[maxn] = {0},maxlevel = -1;
void DFS(int root,int level) {
    if(node[root].size() == 0) { //叶子节点
        hashtable[level]++;
        maxlevel = max(maxlevel,level);
        return ;
    }
    for(int i = 0; i < node[root].size(); ++i)
        DFS(node[root][i],level+1);
}

int main() {
    int n,m,parent,k,child;
    cin>>n>>m;
    for(int i = 0 ; i < m; ++i) {
        cin>>parent>>k;
        for(int j = 0; j < k; ++j) {
            cin>>child;
            node[parent].push_back(child);
        }
    }
    DFS(1,1);
    for(int i = 1; i <= maxlevel; ++i) {
        if(i > 1) printf(" ");
        printf("%d",hashtable[i]);
    }
    return 0;
}