Problem p02598 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define codefor                                                                \\
  int test;                                                                    \\
  scanf("%d", &test);                                                          \\
  while (test--)
#define yn(ans)                                                                \\
  if (ans)                                                                     \\
    printf("Yes\\n");                                                           \\
  else                                                                         \\
    printf("No\\n")
#define YN(ans)                                                                \\
  if (ans)                                                                     \\
    printf("YES\\n");                                                           \\
  else                                                                         \\
    printf("NO\\n")
#define vector2d(type, name, h, ...)                                           \\
  vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define umap unordered_map
#define uset unordered_set
using namespace std;
using ll = long long;
const int MOD = 1000000007;
// 入力系
void scan(int &a) { scanf("%d", &a); }
void scan(long long &a) { scanf("%lld", &a); }
template <class T> void scan(T &a) { cin >> a; }
template <class T> void scan(vector<T> &vec) {
  for (auto &&it : vec)
    scan(it);
}
void in() {}
template <class Head, class... Tail> void in(Head &head, Tail &...tail) {
  scan(head);
  in(tail...);
}
// 出力系
void print(const int &a) { printf("%d", a); }
void print(const long long &a) { printf("%lld", a); }
void print(const double &a) { printf("%.15lf", a); }
template <class T> void print(const T &a) { cout << a; }
template <class T> void print(const vector<T> &vec) {
  if (vec.empty())
    return;
  print(vec[0]);
  for (auto it = vec.begin(); ++it != vec.end();) {
    putchar(' ');
    print(*it);
  }
}
void out() { putchar('\\n'); }
template <class T> void out(const T &t) {
  print(t);
  putchar('\\n');
}
template <class Head, class... Tail>
void out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
}
// デバッグ系
template <class T> void dprint(const T &a) { cerr << a; }
template <class T> void dprint(const vector<T> &vec) {
  if (vec.empty())
    return;
  cerr << vec[0];
  for (auto it = vec.begin(); ++it != vec.end();) {
    cerr << " " << *it;
  }
}
void debug() { cerr << endl; }
template <class T> void debug(const T &t) {
  dprint(t);
  cerr << endl;
}
template <class Head, class... Tail>
void debug(const Head &head, const Tail &...tail) {
  dprint(head);
  cerr << " ";
  debug(tail...);
}
ll intpow(ll a, ll b) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans *= a;
    a *= a;
    b /= 2;
  }
  return ans;
}
ll modpow(ll a, ll b, ll p) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      (ans *= a) %= p;
    (a *= a) %= p;
    b /= 2;
  }
  return ans;
}

int main() {
  int n, k, d, sum = 0;
  ll sum1 = 0, sum2 = 0, sum3 = 0, sum4 = 0;
  in(n, k);
  vector<int> vec(n);
  rep(i, n) {
    in(vec[i]);
    sum1 += (ll)(vec[i] - 1);
    sum2 += (ll)(vec[i] - 1) / 2;
    sum3 += (ll)(vec[i] - 1) / 3;
    sum4 += (ll)(vec[i] - 1) / 4;
  }
  if (sum1 <= k) {
    out(1);
    return 0;
  }
  if (sum2 <= k) {
    out(2);
    return 0;
  }
  if (sum3 <= k) {
    out(3);
    return 0;
  }
  if (sum4 <= k) {
    out(4);
    return 0;
  }
  sort(all(vec));
  int l = 4, r = vec[n - 1], m = (l + r) / 2;
  while (m != l) {
    sum = 0;
    for (int i = 1; 1; i++) {
      d = n - (int)(upper_bound(all(vec), (ll)i * m) - vec.begin());
      if (d == 0)
        break;
      sum += d;
    }
    if (sum <= k)
      r = m;
    else
      l = m;
    m = (l + r) / 2;
  }
  out(m + 1);
}

Error: TLE

Fixed submission:

#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define codefor                                                                \\
  int test;                                                                    \\
  scanf("%d", &test);                                                          \\
  while (test--)
#define yn(ans)                                                                \\
  if (ans)                                                                     \\
    printf("Yes\\n");                                                           \\
  else                                                                         \\
    printf("No\\n")
#define YN(ans)                                                                \\
  if (ans)                                                                     \\
    printf("YES\\n");                                                           \\
  else                                                                         \\
    printf("NO\\n")
#define vector2d(type, name, h, ...)                                           \\
  vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define umap unordered_map
#define uset unordered_set
using namespace std;
using ll = long long;
const int MOD = 1000000007;
// 入力系
void scan(int &a) { scanf("%d", &a); }
void scan(long long &a) { scanf("%lld", &a); }
template <class T> void scan(T &a) { cin >> a; }
template <class T> void scan(vector<T> &vec) {
  for (auto &&it : vec)
    scan(it);
}
void in() {}
template <class Head, class... Tail> void in(Head &head, Tail &...tail) {
  scan(head);
  in(tail...);
}
// 出力系
void print(const int &a) { printf("%d", a); }
void print(const long long &a) { printf("%lld", a); }
void print(const double &a) { printf("%.15lf", a); }
template <class T> void print(const T &a) { cout << a; }
template <class T> void print(const vector<T> &vec) {
  if (vec.empty())
    return;
  print(vec[0]);
  for (auto it = vec.begin(); ++it != vec.end();) {
    putchar(' ');
    print(*it);
  }
}
void out() { putchar('\\n'); }
template <class T> void out(const T &t) {
  print(t);
  putchar('\\n');
}
template <class Head, class... Tail>
void out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
}
// デバッグ系
template <class T> void dprint(const T &a) { cerr << a; }
template <class T> void dprint(const vector<T> &vec) {
  if (vec.empty())
    return;
  cerr << vec[0];
  for (auto it = vec.begin(); ++it != vec.end();) {
    cerr << " " << *it;
  }
}
void debug() { cerr << endl; }
template <class T> void debug(const T &t) {
  dprint(t);
  cerr << endl;
}
template <class Head, class... Tail>
void debug(const Head &head, const Tail &...tail) {
  dprint(head);
  cerr << " ";
  debug(tail...);
}
ll intpow(ll a, ll b) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      ans *= a;
    a *= a;
    b /= 2;
  }
  return ans;
}
ll modpow(ll a, ll b, ll p) {
  ll ans = 1;
  while (b) {
    if (b & 1)
      (ans *= a) %= p;
    (a *= a) %= p;
    b /= 2;
  }
  return ans;
}

int main() {
  int n, k, d, sum = 0;
  ll sum1 = 0, sum2 = 0;
  in(n, k);
  vector<int> vec(n);
  rep(i, n) {
    in(vec[i]);
    sum1 += (ll)vec[i] - 1;
    sum2 += (ll)((vec[i] / 2) - 1);
  }
  if (sum1 <= k) {
    out(1);
    return 0;
  }
  if (sum2 <= k) {
    out(2);
    return 0;
  }
  sort(all(vec));
  int l = 2, r = vec[n - 1], m = (l + r) / 2;
  while (m != l) {
    sum = 0;
    for (int i = 1; 1; i++) {
      d = n - (int)(upper_bound(all(vec), (ll)i * m) - vec.begin());
      if (d == 0)
        break;
      sum += d;
    }
    if (sum <= k)
      r = m;
    else
      l = m;
    m = (l + r) / 2;
  }
  out(m + 1);
}