[Link] https://www.acmicpc.net/problem/1135
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
#include <algorithm>
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <cstring>
// #include <bits/stdc++.h>
using namespace std;
#define for0(i, n) for(int i = 0; i < n; i++)
#define for1(i, n) for(int i = 1; i < n; i++)
#define fori(s, e) for(int i = s; i < e; i++)
#define ll long long
#define endl "\n"
#define nulls '\0'
#define dkdk " "
const int MAX = 5e5 + 1;
const int INF = 987654321;
int n, m, min_time;
vector<vector<int>> child;
int dfs(int idx) {
if(child[idx].size() == 0) return 0;
vector<int> vec;
for(int child_idx: child[idx]) {
vec.push_back(dfs(child_idx));
}
int local_min = 0, t_local = 0;
sort(vec.begin(), vec.end(), greater<int>());
for0(i, vec.size()) {
local_min = max(local_min, i+1 + vec[i]);
}
return local_min;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
child.resize(n);
int in; cin >> in;
for1(i, n) {
int in; cin >> in;
child[in].push_back(i);
}
cout << dfs(0);
return 0;
}