Problem p02548 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
typedef vector<ll> vl;
typedef vector<int> vi;
typedef vector<char> vec;
typedef vector<bool> veb;
typedef vector<string> ves;
typedef vector<vector<ll>> vvl;
typedef vector<vector<int>> vvi;
typedef vector<vector<char>> vvec;
typedef vector<vector<bool>> vveb;
typedef vector<vector<string>> vves;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n); i++)
#define rep2(i, n) for (int i = 2; i < (int)(n); i++)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define rev(v) reverse(v.begin(), v.end())
#define fs first
#define sc second
#define pb push_back
#define pp pop_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define maxel(a) *max_element(all(a))
#define minel(a) *min_element(all(a))
#define acc accumulate
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
#define mod (1000000007)
typedef long long int64;
// const int64 INF = 1LL << 58;
#define dame                                                                   \\
  {                                                                            \\
    puts("-1");                                                                \\
    return 0;                                                                  \\
  }
#define YES                                                                    \\
  {                                                                            \\
    cout << "YES" << endl;                                                     \\
    return 0;                                                                  \\
  }
#define NO                                                                     \\
  {                                                                            \\
    cout << "NO" << endl;                                                      \\
    return 0;                                                                  \\
  }
#define Yes                                                                    \\
  {                                                                            \\
    cout << "Yes" << endl;                                                     \\
    return 0;                                                                  \\
  }
#define No                                                                     \\
  {                                                                            \\
    cout << "No" << endl;                                                      \\
    return 0;                                                                  \\
  }
#define uniq(a)                                                                \\
  sort(all(a));                                                                \\
  (a).resize(unique(all(a)) - a.begin());
#define dab(v)                                                                 \\
  for (auto i : v)                                                             \\
    cout << i << ' ' << endl;
#define vin(v)                                                                 \\
  for (ll i = 0; i < v.size(); ++i)                                            \\
    cin >> v[i];
#define vin2(v, w)                                                             \\
  for (ll i = 0; i < v.size(); ++i)                                            \\
    cin >> v[i] >> w[i];
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int dx[] = {0, 0, -1, 1};
int dy[] = {1, -1, 0, 0};
int gcd(int a, int b) {
  if (a % b == 0) {
    return (b);
  } else {
    return (gcd(b, a % b));
  }
}

template <typename T> map<T, T> prime_factor(T n) {
  map<T, T> ret;
  for (T i = 2; i * i <= n; i++) {
    T tmp = 0;
    while (n % i == 0) {
      tmp++;
      n /= i;
    }
    ret[i] = tmp;
  }
  if (n != 1)
    ret[n] = 1;
  return ret;
}

template <typename T> T divisor_num(T N) {
  map<T, T> pf = prime_factor(N);
  T ret = 1;
  for (auto p : pf) {
    ret *= (p.second + 1);
  }
  return ret;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  // cout << fixed << setprecision(18);

  long long N;
  cin >> N;
  long long int cnt = 0;

  repk(i, 1, N) {
    cnt += floor((double)(N - 1) / (double)i);
    // cout << i << " " << cnt << endl;
  }
  cout << cnt;

  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
typedef vector<ll> vl;
typedef vector<int> vi;
typedef vector<char> vec;
typedef vector<bool> veb;
typedef vector<string> ves;
typedef vector<vector<ll>> vvl;
typedef vector<vector<int>> vvi;
typedef vector<vector<char>> vvec;
typedef vector<vector<bool>> vveb;
typedef vector<vector<string>> vves;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n); i++)
#define rep2(i, n) for (int i = 2; i < (int)(n); i++)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define rev(v) reverse(v.begin(), v.end())
#define fs first
#define sc second
#define pb push_back
#define pp pop_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define maxel(a) *max_element(all(a))
#define minel(a) *min_element(all(a))
#define acc accumulate
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))
#define mod (1000000007)
typedef long long int64;
// const int64 INF = 1LL << 58;
#define dame                                                                   \\
  {                                                                            \\
    puts("-1");                                                                \\
    return 0;                                                                  \\
  }
#define YES                                                                    \\
  {                                                                            \\
    cout << "YES" << endl;                                                     \\
    return 0;                                                                  \\
  }
#define NO                                                                     \\
  {                                                                            \\
    cout << "NO" << endl;                                                      \\
    return 0;                                                                  \\
  }
#define Yes                                                                    \\
  {                                                                            \\
    cout << "Yes" << endl;                                                     \\
    return 0;                                                                  \\
  }
#define No                                                                     \\
  {                                                                            \\
    cout << "No" << endl;                                                      \\
    return 0;                                                                  \\
  }
#define uniq(a)                                                                \\
  sort(all(a));                                                                \\
  (a).resize(unique(all(a)) - a.begin());
#define dab(v)                                                                 \\
  for (auto i : v)                                                             \\
    cout << i << ' ' << endl;
#define vin(v)                                                                 \\
  for (ll i = 0; i < v.size(); ++i)                                            \\
    cin >> v[i];
#define vin2(v, w)                                                             \\
  for (ll i = 0; i < v.size(); ++i)                                            \\
    cin >> v[i] >> w[i];
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int dx[] = {0, 0, -1, 1};
int dy[] = {1, -1, 0, 0};
int gcd(int a, int b) {
  if (a % b == 0) {
    return (b);
  } else {
    return (gcd(b, a % b));
  }
}

template <typename T> map<T, T> prime_factor(T n) {
  map<T, T> ret;
  for (T i = 2; i * i <= n; i++) {
    T tmp = 0;
    while (n % i == 0) {
      tmp++;
      n /= i;
    }
    ret[i] = tmp;
  }
  if (n != 1)
    ret[n] = 1;
  return ret;
}

template <typename T> T divisor_num(T N) {
  map<T, T> pf = prime_factor(N);
  T ret = 1;
  for (auto p : pf) {
    ret *= (p.second + 1);
  }
  return ret;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  // cout << fixed << setprecision(18);

  long long N;
  cin >> N;
  // cout << divisor_num(N) << endl;
  int cnt = 0;
  repk(i, 1, N) {
    // cout << i << " " << divisor_num(i) << endl;
    cnt += divisor_num(i);
  }
  cout << cnt;
  return 0;
}