Problem p02598 (C++)

Buggy submission (status: Runtime Error):
/**
 *    author:  otera
 **/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

#define int long long
typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cerr << #x << " = " << (x) << endl;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

int n, k;
vector<int> a;

bool check(int x) {
  int cnt = 0;
  rep(i, n) {
    if (a[i] <= x)
      continue;
    cnt += (a[i] - 1) / x;
  }
  return (cnt <= k);
}

void solve() {
  cin >> n >> k;
  a.resize(n);
  rep(i, n) { cin >> a[i]; }
  int ok = inf, ng = -1;
  while (ok - ng > 1) {
    int mid = (ok + ng) / 2;
    if (check(mid))
      ok = mid;
    else
      ng = mid;
  }
  cout << ok << endl;
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // int t; cin >> t; rep(i, t)solve();
  solve();
  return 0;
}

Fixed submission:
/**
 *    author:  otera
 **/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

#define int long long
typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cerr << #x << " = " << (x) << endl;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

int n, k;
vector<int> a;

bool check(int x) {
  int cnt = 0;
  rep(i, n) {
    if (a[i] <= x)
      continue;
    cnt += (a[i] - 1) / x;
  }
  return (cnt <= k);
}

void solve() {
  cin >> n >> k;
  a.resize(n);
  rep(i, n) { cin >> a[i]; }
  int ok = inf, ng = 0;
  while (ok - ng > 1) {
    int mid = (ok + ng) / 2;
    if (check(mid))
      ok = mid;
    else
      ng = mid;
  }
  cout << ok << endl;
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // int t; cin >> t; rep(i, t)solve();
  solve();
  return 0;
}