Problem p02707 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
// #include<ext/pb_ds/assoc_container.hpp>
// #include<ext/pb_ds/tree_policy.hpp>
//
//     #pragma GCC optimize("unroll-loops")
//     #pragma GCC optimize("Ofast")
//     #pragma GCC optimize("-O3")
//     #pragma GCC optimize("no-stack-protector")
//     #pragma GCC optimize("fast-math")

#define fi first
#define f first
#define se second
#define s second
#define vi_a vector<int> a;
#define p_b emplace_back
////////////////////////////////???????????????CHECK THIS
///OUT???????????????//////////////////////////////
#define ll long long
////////////////////////////////???????????????CHECK THIS
///OUT???????????????//////////////////////////////
#define ld long double
#define pll pair<ll, ll>
#define pii pair<int, int>
#define m_p make_pair
#define fast_io                                                                \\
  cin.tie(0);                                                                  \\
  cout.tie(0);                                                                 \\
  ios_base::sync_with_stdio(0);
#define all(x) x.begin(), x.end()
#define getfiles                                                               \\
  ifstream cin("input.txt");                                                   \\
  ofstream cout("output.txt");
#define pw(x) (1ll << x)
#define sz(x) (ll) x.size()
#define endl "\\n"
#define rall(x) x.rbegin(), x.rend()
#define len(a) (ll) a.size()
#define rep(x, l, r) for (ll x = l; x < r; x++)
// #define for(int i=0;i<n;i++) for(ll i=0;i<n;i++)
using namespace std;
// using namespace __gnu_pbds;
ld eps = (ld)1 / 1e7;
ll inf = 1e18, mod2 = 998244353, mod1 = 1e9 + 7;
ll sqr(ll a) { return a * a; }
ll qb(ll a) { return a * a * a; }
ll gcd(ll a, ll b) { return !a ? b : gcd(b % a, a); }
ll binpow(ll a, ll b, ll mod) {
  return b ? (b % 2 ? (a * (sqr(binpow(a, b / 2, mod)) % mod)) % mod
                    : sqr(binpow(a, b / 2, mod)) % mod)
           : 1;
}
ll binmult(ll a, ll b, ll mod) {
  return b ? (b % 2 ? (2 * binmult(a, b / 2, mod) + a) % mod
                    : (2 * binmult(a, b / 2, mod)) % mod)
           : 0;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// const ll to[5]={0,4,6,7,9};
// const ll N=2*1e5+1;
const ll R = 1e4;
// const ll to[7]={1,2,3,1,3,2,1};
const ll tx[4] = {2, -1, 2, 1};
const ll ty[4] = {-1, 2, 1, 2};
const char rev_to[4] = {'E', 'W', 'N', 'S'};
const int N = 2 * 1e5 + 1;
ll dp[N];
bool used[N];
vector<ll> g[N];
void dfs(ll v, ll p) {
  dp[v] = 1;
  for (auto u : g[v]) {
    if (u == p)
      continue;
    dfs(u, v);
    dp[v] += dp[u];
  }
}
signed main() {
  ll n;
  cin >> n;
  ll v;
  for (ll i = 1; i < n; i++) {
    cin >> v;
    --v;
    g[v].p_b(i);
  }
  //    for(ll i=0;i<n;i++){
  //        if(!used[i]){
  //            dfs(i,-1);
  //        }
  //    }
  for (ll i = 0; i < n; i++) {
    cout << sz(g[i]) << endl;
  }
  return 0;
}
/*

    если WA , то чекер говно, поэтому почекай l8 строчку

*/


Error: 0

Fixed submission:

#include <bits/stdc++.h>
// #include<ext/pb_ds/assoc_container.hpp>
// #include<ext/pb_ds/tree_policy.hpp>
//
//     #pragma GCC optimize("unroll-loops")
//     #pragma GCC optimize("Ofast")
//     #pragma GCC optimize("-O3")
//     #pragma GCC optimize("no-stack-protector")
//     #pragma GCC optimize("fast-math")

#define fi first
#define f first
#define se second
#define s second
#define vi_a vector<int> a;
#define p_b emplace_back
////////////////////////////////???????????????CHECK THIS
///OUT???????????????//////////////////////////////
#define ll long long
////////////////////////////////???????????????CHECK THIS
///OUT???????????????//////////////////////////////
#define ld long double
#define pll pair<ll, ll>
#define pii pair<int, int>
#define m_p make_pair
#define fast_io                                                                \\
  cin.tie(0);                                                                  \\
  cout.tie(0);                                                                 \\
  ios_base::sync_with_stdio(0);
#define all(x) x.begin(), x.end()
#define getfiles                                                               \\
  ifstream cin("input.txt");                                                   \\
  ofstream cout("output.txt");
#define pw(x) (1ll << x)
#define sz(x) (ll) x.size()
#define endl "\\n"
#define rall(x) x.rbegin(), x.rend()
#define len(a) (ll) a.size()
#define rep(x, l, r) for (ll x = l; x < r; x++)
// #define for(int i=0;i<n;i++) for(ll i=0;i<n;i++)
using namespace std;
// using namespace __gnu_pbds;
ld eps = (ld)1 / 1e7;
ll inf = 1e18, mod2 = 998244353, mod1 = 1e9 + 7;
ll sqr(ll a) { return a * a; }
ll qb(ll a) { return a * a * a; }
ll gcd(ll a, ll b) { return !a ? b : gcd(b % a, a); }
ll binpow(ll a, ll b, ll mod) {
  return b ? (b % 2 ? (a * (sqr(binpow(a, b / 2, mod)) % mod)) % mod
                    : sqr(binpow(a, b / 2, mod)) % mod)
           : 1;
}
ll binmult(ll a, ll b, ll mod) {
  return b ? (b % 2 ? (2 * binmult(a, b / 2, mod) + a) % mod
                    : (2 * binmult(a, b / 2, mod)) % mod)
           : 0;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// const ll to[5]={0,4,6,7,9};
// const ll N=2*1e5+1;
const ll R = 1e4;
// const ll to[7]={1,2,3,1,3,2,1};
const ll tx[4] = {2, -1, 2, 1};
const ll ty[4] = {-1, 2, 1, 2};
const char rev_to[4] = {'E', 'W', 'N', 'S'};
const int N = 3001;
ll dp[N];
bool used[N];
vector<ll> g[N];
void dfs(ll v, ll p) {
  dp[v] = 1;
  for (auto u : g[v]) {
    if (u == p)
      continue;
    dfs(u, v);
    dp[v] += dp[u];
  }
}
signed main() {
  ll n;
  cin >> n;
  ll v;
  for (ll i = 1; i < n; i++) {
    cin >> v;
    --v;
    g[v].p_b(i);
  }
  //    for(ll i=0;i<n;i++){
  //        if(!used[i]){
  //            dfs(i,-1);
  //        }
  //    }
  for (ll i = 0; i < n; i++) {
    cout << sz(g[i]) << endl;
  }
  return 0;
}
/*

    если WA , то чекер говно, поэтому почекай l8 строчку

*/