Problem p02598 (C++) — buggy submission, verdict: Runtime Error

// Nihal Mittal - nihal_47
// Strike First , Strike Hard , No Mercy !!

/**⠀⠀⠀⠀⠀⠀⣀⣤⣤⣄⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⣠⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣦⣀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⣰⣿⣿⣿⣿⠿⠿⣿⣿⣿⣿⣿⣿⣿⣧⢀⠀⠀⠀⠀
⠀⠀⠀⣿⣿⣿⠋⠀⠀⠀⠀⠀⠙⠀⠙⣿⣿⣿⣷⢳⢀⠀⠀⠀
⠀⠀⣠⣿⣿⣿⢸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⣿⣿⣿⣿⢀
⠀⠀⣸⣿⣿⣿⠸⠀⠀⠀⠒⠒⠒⠐⠀⠀⢿⣿⣿⣿⣿⣿⠀⠀
⠀⣴⣿⣿⣿⡿⠀⠒⣋⣙⡒⢰⠀⠤⣖⠒⢾⣿⣿⣿⣿⣧⠀⠀
⢺⣿⣿⣿⣿⢀⠀⠀⠉⠉⠉⠸⠀⡇⠉⠉⠀⢿⣿⣿⣿⣄⠀⠀
⠀⠙⣿⣿⣧⢻⠀⠀⠀⠀⠀⠠⠀⠰⠀⠀⠀⣸⠸⣿⣿⠿⠰⠀
⠀⠀⠀⠹⣿⣿⣿⣷⠀⡠⠙⣲⣔⣅⢡⣰⣷⣿⣿⣿⣧⠀⠀⠀
⠀⠀⠀⣼⣿⣿⣿⣿⠀⡿⠭⠭⠭⠭⢿⠀⣿⢻⣿⣿⠃⠀⠀⠀
⠀⠀⠀⠙⠛⣿⢻⠹⣿⠐⠙⠛⠟⠉⢀⣴⡟⢿⣿⡏⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⡟⠀⠀⠻⣦⣤⣶⠾⠋⠀⠀⠁⡦⢄⢀⠀⠀⠀
⠀⠀⠀⠀⡠⠁⡇⠑⢄⠀⠀⠀⠀⠀⠀⠔⠀⠀⠁⠀⠀⠀⠉⠁
⠀⠔⠊⠁⠀⠀⣇⠀⠀⠀⠑⡤⠤⢎⠁⠀⠀⡘⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⢢⠠⠀⡠⢆⠀⠀⡠⠙⢄⠀⡸⠀
**/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define mk make_pair
#define pb push_back
#define in insert
#define se second
#define fi first
#define mod 1000000007
#define watch(x) cout << (#x) << " is " << (x) << "\\n"
#define all(v) (v).begin(), (v).end()
#define fast                                                                   \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(0);
#define printclock                                                             \\
  cerr << "Time : " << 1000 * (ld)clock() / (ld)CLOCKS_PER_SEC << "ms\\n";
#define pii pair<ll, ll>
#define vi(x) vector<x>
#define maxn 100005
#define ordered_set                                                            \\
  tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>
using namespace std;
using namespace __gnu_pbds;

signed main() {
  fast;

  ll n, k, i;
  cin >> n >> k;
  ll a[n + 2];
  for (i = 0; i < n; i++)
    cin >> a[i];

  ll lo = 1, hi = 10000000000000;
  while (hi > lo) {
    ll sum = 0, mid = (hi + lo) / 2;
    for (i = 0; i < n; i++) {
      sum += (a[i] - 1) / mid;
    }
    if (sum <= k)
      hi = mid;
    else
      lo = mid + 1;
  }
  cout << hi;
}

Error: WA

Fixed submission:

// Nihal Mittal - nihal_47
// Strike First , Strike Hard , No Mercy !!

/**⠀⠀⠀⠀⠀⠀⣀⣤⣤⣄⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⣠⣾⣿⣿⣿⣿⣿⣿⣿⣿⣿⣦⣀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⣰⣿⣿⣿⣿⠿⠿⣿⣿⣿⣿⣿⣿⣿⣧⢀⠀⠀⠀⠀
⠀⠀⠀⣿⣿⣿⠋⠀⠀⠀⠀⠀⠙⠀⠙⣿⣿⣿⣷⢳⢀⠀⠀⠀
⠀⠀⣠⣿⣿⣿⢸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⣿⣿⣿⣿⢀
⠀⠀⣸⣿⣿⣿⠸⠀⠀⠀⠒⠒⠒⠐⠀⠀⢿⣿⣿⣿⣿⣿⠀⠀
⠀⣴⣿⣿⣿⡿⠀⠒⣋⣙⡒⢰⠀⠤⣖⠒⢾⣿⣿⣿⣿⣧⠀⠀
⢺⣿⣿⣿⣿⢀⠀⠀⠉⠉⠉⠸⠀⡇⠉⠉⠀⢿⣿⣿⣿⣄⠀⠀
⠀⠙⣿⣿⣧⢻⠀⠀⠀⠀⠀⠠⠀⠰⠀⠀⠀⣸⠸⣿⣿⠿⠰⠀
⠀⠀⠀⠹⣿⣿⣿⣷⠀⡠⠙⣲⣔⣅⢡⣰⣷⣿⣿⣿⣧⠀⠀⠀
⠀⠀⠀⣼⣿⣿⣿⣿⠀⡿⠭⠭⠭⠭⢿⠀⣿⢻⣿⣿⠃⠀⠀⠀
⠀⠀⠀⠙⠛⣿⢻⠹⣿⠐⠙⠛⠟⠉⢀⣴⡟⢿⣿⡏⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⡟⠀⠀⠻⣦⣤⣶⠾⠋⠀⠀⠁⡦⢄⢀⠀⠀⠀
⠀⠀⠀⠀⡠⠁⡇⠑⢄⠀⠀⠀⠀⠀⠀⠔⠀⠀⠁⠀⠀⠀⠉⠁
⠀⠔⠊⠁⠀⠀⣇⠀⠀⠀⠑⡤⠤⢎⠁⠀⠀⡘⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⢢⠠⠀⡠⢆⠀⠀⡠⠙⢄⠀⡸⠀
**/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define mk make_pair
#define pb push_back
#define in insert
#define se second
#define fi first
#define mod 1000000007
#define watch(x) cout << (#x) << " is " << (x) << "\\n"
#define all(v) (v).begin(), (v).end()
#define fast                                                                   \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(0);
#define printclock                                                             \\
  cerr << "Time : " << 1000 * (ld)clock() / (ld)CLOCKS_PER_SEC << "ms\\n";
#define pii pair<ll, ll>
#define vi(x) vector<x>
#define maxn 100005
#define ordered_set                                                            \\
  tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>
using namespace std;
using namespace __gnu_pbds;

signed main() {
  fast;

  ll n, k, i;
  cin >> n >> k;
  ll a[n + 2];
  for (i = 0; i < n; i++)
    cin >> a[i];

  ll lo = 0, hi = 10000000000000;
  while (hi > lo) {
    ll sum = 0, mid = (hi + lo) / 2;
    for (i = 0; i < n; i++) {
      sum += (a[i] - 1) / mid;
    }
    if (sum <= k)
      hi = mid;
    else
      lo = mid + 1;
  }
  cout << hi;
}