Problem p02722 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int(i) = 0; (i) < (n); (i)++)
#define repp(i, m, n) for (int(i) = (m); (i) < (n); (i)++)
#define repm(i, n) for (int(i) = (n - 1); (i) >= 0; (i)--)
#define INF (1ll << 60)
#define all(x) (x).begin(), (x).end()
typedef long long lint;
const lint MOD = 1000000007;
const lint MAX = 10000000;
using Graph = vector<vector<lint>>;
typedef pair<lint, lint> P;

lint fac[MAX], finv[MAX], inv[MAX];

void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (lint i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

long long COM(lint n, lint k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

lint primary(lint num) {
  if (num < 2)
    return 0;
  else if (num == 2)
    return 1;
  else if (num % 2 == 0)
    return 0;

  double sqrtNum = sqrt(num);
  for (int i = 3; i <= sqrtNum; i += 2) {
    if (num % i == 0) {
      return 0;
    }
  }

  return 1;
}
long long modpow(long long a, long long n, long long mod) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
lint lcm(lint a, lint b) { return a / __gcd(a, b) * b; }
lint gcd(lint a, lint b) { return __gcd(a, b); }

int main() {
  lint n;
  cin >> n;
  lint t = n - 1;
  set<lint> st;
  lint ans = 1;
  lint count = 0;
  rep(i, sqrt(t)) {
    if (t % (i + 1) == 0) {
      st.insert(t / (i + 1));
      if (i == 0)
        continue;
      st.insert(i + 1);
    }
  }

  count = st.size();
  rep(i, sqrt(n)) {
    lint k = n;
    if (n % (i + 1) == 0) {
      lint j = n / (i + 1);
      if (j == 1)
        continue;
      while (k % j == 0) {
        k /= j;
      }
      if (k == 1 || k % j == 1)
        st.insert(j);
      k = n;
      if (i == 0)
        continue;
      while (k % (i + 1) == 0) {
        k /= (i + 1);
      }
      if (k == 1 || k % (i + 1) == 1)
        st.insert(i + 1);
    }
  }
  st.insert(1);
  st.erase(1);
  cout << st.size();
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int(i) = 0; (i) < (n); (i)++)
#define repp(i, m, n) for (int(i) = (m); (i) < (n); (i)++)
#define repm(i, n) for (int(i) = (n - 1); (i) >= 0; (i)--)
#define INF (1ll << 60)
#define all(x) (x).begin(), (x).end()
typedef long long lint;
const lint MOD = 1000000007;
const lint MAX = 10000000;
using Graph = vector<vector<lint>>;
typedef pair<lint, lint> P;

lint fac[MAX], finv[MAX], inv[MAX];

void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (lint i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}

long long COM(lint n, lint k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

lint primary(lint num) {
  if (num < 2)
    return 0;
  else if (num == 2)
    return 1;
  else if (num % 2 == 0)
    return 0;

  double sqrtNum = sqrt(num);
  for (int i = 3; i <= sqrtNum; i += 2) {
    if (num % i == 0) {
      return 0;
    }
  }

  return 1;
}
long long modpow(long long a, long long n, long long mod) {
  long long res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}
lint lcm(lint a, lint b) { return a / __gcd(a, b) * b; }
lint gcd(lint a, lint b) { return __gcd(a, b); }

int main() {
  lint n;
  cin >> n;
  lint t = n - 1;
  set<lint> st;
  lint ans = 1;
  lint count = 0;
  rep(i, sqrt(t) + 1) {
    if (t % (i + 1) == 0) {
      st.insert(t / (i + 1));
      if (i == 0)
        continue;
      st.insert(i + 1);
    }
  }

  count = st.size();
  rep(i, sqrt(n)) {
    lint k = n;
    if (n % (i + 1) == 0) {
      lint j = n / (i + 1);
      while (k % j == 0) {
        k /= j;
      }
      if (k == 1 || k % j == 1)
        st.insert(j);
      k = n;
      if (i == 0)
        continue;
      while (k % (i + 1) == 0) {
        k /= (i + 1);
      }
      if (k == 1 || k % (i + 1) == 1)
        st.insert(i + 1);
    }
  }
  cout << st.size();
}