Problem p02658 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;

#define ff first
#define ss second
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define vi vector<int>
#define mii map<int, int>
#define pqb priority_queue<int>
#define pqs priority_queue<int, vi, greater<int>>
#define setbits(x) __builtin_popcountll(x)
#define zrobits(x) __builtin_ctzll(x)
#define mod 1000000007
#define inf 1e18
#define ps(x, y) fixed << setprecision(y) << x
#define mk(arr, n, type) type *arr = new type[n];
#define w(x)                                                                   \
  int x;                                                                       \
  cin >> x;                                                                    \
  while (x--)
#define pw(b, p) pow(b, p) + 0.1

#ifndef ONLINE_JUDGE
#define watch(x) cerr << #x << " = " << x << "\n"
#else
#define watch(x) 42
#endif

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    pbds;

void c_p_c() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
  freopen("debug.txt", "w", stderr);
#endif
}

int dig(int n) {
  int d = 0;

  while (n != 0) {
    d++;
    n /= 10;
  }

  return d;
}

int32_t main() {
  c_p_c();

  int n;
  cin >> n;

  int a[n];

  int mx = 1e18;

  int ans = 1;

  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }

  sort(a, a + n);

  for (int i = 0; i < n; ++i) {
    // cout << ans << '\n';

    if (ans == -1)
      continue;

    if (a[i] > ceil(mx / ans)) {
      ans = -1;
    } else
      ans *= a[i];
  }

  if (ans > mx)
    ans = -1;

  cout << ans;

  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;

#define ff first
#define ss second
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define vi vector<int>
#define mii map<int, int>
#define pqb priority_queue<int>
#define pqs priority_queue<int, vi, greater<int>>
#define setbits(x) __builtin_popcountll(x)
#define zrobits(x) __builtin_ctzll(x)
#define mod 1000000007
#define inf 1e18
#define ps(x, y) fixed << setprecision(y) << x
#define mk(arr, n, type) type *arr = new type[n];
#define w(x)                                                                   \
  int x;                                                                       \
  cin >> x;                                                                    \
  while (x--)
#define pw(b, p) pow(b, p) + 0.1

#ifndef ONLINE_JUDGE
#define watch(x) cerr << #x << " = " << x << "\n"
#else
#define watch(x) 42
#endif

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    pbds;

void c_p_c() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
  freopen("debug.txt", "w", stderr);
#endif
}

int dig(int n) {
  int d = 0;

  while (n != 0) {
    d++;
    n /= 10;
  }

  return d;
}

int32_t main() {
  c_p_c();

  int n;
  cin >> n;

  int a[n];

  int mx = 1e18;

  int ans = 1;

  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }

  sort(a, a + n);

  for (int i = 0; i < n; ++i) {
    // cout << ans << '\n';

    if (ans == -1)
      continue;

    if (ans != 0 && a[i] > ceil(mx / ans)) {
      ans = -1;
    } else
      ans *= a[i];
  }

  if (ans > mx)
    ans = -1;

  cout << ans;

  return 0;
}