Problem p02598 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vii;
typedef vector<vi> vvi;
typedef vector<pll> vll;
typedef vector<vl> vvl;

#define fori(i, n) for (int i = 0; i < n; i++)
#define ford(i, n) for (int i = n - 1; i >= 0; i--)
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define repd(i, a, b) for (int i = a; i >= b; i--)
#define trav(x, a) for (auto &x : a)
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define eb emplace_back
#define endl '\n'
#define sz(a) (int)(a).size()
#define fi first
#define se second

clock_t time_p = clock();
void time_taken() {
  time_p = clock() - time_p;
  cerr << "Time Taken : " << (float)(time_p) / CLOCKS_PER_SEC << "\n";
}

const ll mod = 1e9 + 7;
const ll INF = 1e18;

const ld EPS = 1e-8;

#define TRACE
#ifdef TRACE
#define trace(...)                                                             \
  {                                                                            \
    cerr << "[ ";                                                              \
    __trace__(#__VA_ARGS__, __VA_ARGS__);                                      \
  }
#undef endl
template <typename Arg1, typename Arg2>
ostream &operator<<(ostream &out, const pair<Arg1, Arg2> &x) {
  return out << "(" << x.first << "," << x.second << ")";
}

template <typename Arg1>
ostream &operator<<(ostream &out, const vector<Arg1> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1> ostream &operator<<(ostream &out, const set<Arg1> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1, typename Arg2>
ostream &operator<<(ostream &out, const map<Arg1, Arg2> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1> void __trace__(const string name, Arg1 &&arg1) {
  cerr << name << " : " << arg1 << " ] " << endl;
}

template <typename Arg1, typename... Args>
void __trace__(const string names, Arg1 &&arg1, Args &&...args) {
  const string name = names.substr(0, names.find(','));
  cerr << name << " : " << arg1 << " | ";
  __trace__(names.substr(1 + (int)name.size()), args...);
}
#else
#define trace(args...)
#endif

int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);

  int n, k;
  cin >> n >> k;
  vi a(n);
  fori(i, n) cin >> a[i];
  ll lo = 0, hi = 1e9;
  ll ans = 1e9;
  while (lo <= hi) {
    ll mid = (lo + hi) / 2;
    ll req = 0;
    fori(i, n) { req += (a[i] + mid - 1) / mid - 1; }
    // trace(mid,req);
    if (req <= k) {
      ans = mid;
      hi = mid - 1;
    } else {
      lo = mid + 1;
    }
  }
  cout << ans << endl;

  time_taken();
  return 0;
}

Fixed submission:
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vii;
typedef vector<vi> vvi;
typedef vector<pll> vll;
typedef vector<vl> vvl;

#define fori(i, n) for (int i = 0; i < n; i++)
#define ford(i, n) for (int i = n - 1; i >= 0; i--)
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define repd(i, a, b) for (int i = a; i >= b; i--)
#define trav(x, a) for (auto &x : a)
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define eb emplace_back
#define endl '\n'
#define sz(a) (int)(a).size()
#define fi first
#define se second

clock_t time_p = clock();
void time_taken() {
  time_p = clock() - time_p;
  cerr << "Time Taken : " << (float)(time_p) / CLOCKS_PER_SEC << "\n";
}

const ll mod = 1e9 + 7;
const ll INF = 1e18;

const ld EPS = 1e-8;

#define TRACE
#ifdef TRACE
#define trace(...)                                                             \
  {                                                                            \
    cerr << "[ ";                                                              \
    __trace__(#__VA_ARGS__, __VA_ARGS__);                                      \
  }
#undef endl
template <typename Arg1, typename Arg2>
ostream &operator<<(ostream &out, const pair<Arg1, Arg2> &x) {
  return out << "(" << x.first << "," << x.second << ")";
}

template <typename Arg1>
ostream &operator<<(ostream &out, const vector<Arg1> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1> ostream &operator<<(ostream &out, const set<Arg1> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1, typename Arg2>
ostream &operator<<(ostream &out, const map<Arg1, Arg2> &a) {
  out << "[";
  for (const auto &x : a)
    out << x << ",";
  return out << "]";
}

template <typename Arg1> void __trace__(const string name, Arg1 &&arg1) {
  cerr << name << " : " << arg1 << " ] " << endl;
}

template <typename Arg1, typename... Args>
void __trace__(const string names, Arg1 &&arg1, Args &&...args) {
  const string name = names.substr(0, names.find(','));
  cerr << name << " : " << arg1 << " | ";
  __trace__(names.substr(1 + (int)name.size()), args...);
}
#else
#define trace(args...)
#endif

int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);

  int n, k;
  cin >> n >> k;
  vi a(n);
  fori(i, n) cin >> a[i];
  ll lo = 1, hi = 1e9;
  ll ans = 1e9;
  while (lo <= hi) {
    ll mid = (lo + hi) / 2;
    ll req = 0;
    fori(i, n) { req += (a[i] + mid - 1) / mid - 1; }
    // trace(mid,req);
    if (req <= k) {
      ans = mid;
      hi = mid - 1;
    } else {
      lo = mid + 1;
    }
  }
  cout << ans << endl;

  time_taken();
  return 0;
}