Homework 2 Task A

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

int main() {
    int n;
    cin >> n;

    vector<vector<int>> graph(n + 1);
    vector<int> distance(n + 1, -1);

    for (int i = 2; i <= n; ++i) {
        int parent;
        cin >> parent;
        graph[parent].push_back(i);
    }

    queue<int> q;
    q.push(1);
    distance[1] = 0;

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

        for (int child: graph[current]) {
            if (distance[child] == -1) {
                distance[child] = distance[current] + 1;
                q.push(child);
            }
        }
    }

    int maxDistance = *max_element(distance.begin(), distance.end());
    vector<int> farthestNodes;
    for (int i = 1; i <= n; ++i) {
        if (distance[i] == maxDistance) {
            farthestNodes.push_back(i);
        }
    }

    cout << maxDistance << endl;
    cout << farthestNodes.size() << endl;
    for (int node: farthestNodes) {
        cout << node << " ";
    }
    cout << endl;

    return 0;
}