Submission #1074366

---

Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int a[100000], d[1000000];

bool u[100000];

int main()
{
    int n;
    cin >> n;
    for (int i = 1; i < n; i++){
        cin >> a[i];
        a[i]--;
        u[a[i]] = 1;
    }

    queue<int> q;
    for (int i = 0; i < n; i++)
        if (!u[i]){
            q.push(i);
            d[i] = 0;
        }
    for (int i = 0; i < n; i++)
        u[i] = 0;

    while (!q.empty()){
        int v = q.front();
        q.pop();

        d[a[v]] = max(d[a[v]], d[v] + 1);
        if (!u[a[v]]){
            q.push(a[v]);
            u[a[v]] = 1;
        }
    }

    cout << d[0] << '\n';
    return 0;
}

Submission Info

Judge Result