---
title: "L2-026 小字辈"
created: 2025-11-28
tags:
  - 算法
---

# L2-026 小字辈

## 题目 [L2-026 小字辈](https://pintia.cn/problem-sets/994805046380707840/exam/problems/type/7?problemSetProblemId=994805055679479808&page=1)

![[image-8ac5a29c.png]]

## 思路分析

## 代码实现

```cpp
#include<bits/stdc++.h>

using namespace std;

#define endl '\n'

using ll = long long;

using ull = unsigned long long;

using PII = pair<int,int>;

using Pll = pair<ll,ll>;

int dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};

const int inf = 0x3f3f3f3f;

priority_queue<int> pq;

multiset<int> s;

vector<vector<int>> g;

int maxDeep=-inf;

vector<int> ans;

void dfs(int u,int deep){

	if(deep>=maxDeep){

		if(deep>maxDeep){

			ans.clear();

			maxDeep=deep;

			ans.push_back(u);

		}

		else if(deep==maxDeep){

			ans.push_back(u);

		}

	}

	for(auto nx:g[u]){

		dfs(nx,deep+1);

	}

}

int main(){

	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);

	int n;cin>>n;

	g.resize(n+1);

	vector<int> roots;

	for(int i=1;i<=n;i++){

		int fa;cin>>fa;

		if(fa==-1)	roots.push_back(i);

		else g[fa].push_back(i);

	}

	for(auto r:roots)	dfs(r, 1);

	cout<<maxDeep<<endl;

	bool isFirst=true;

	for(auto v:ans)	 {

		if(!isFirst)	cout<<" ";

		cout<<v;

		isFirst=false;

	}

	return 0;

}
```

## 同类题型

## 视频讲解

---
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