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

#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string.h>
#include <string>
#include <tuple>
#include <vector>
using namespace std;
#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define pp(...) "\\033[94m [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\\033[0m"
#define pp1(...)                                                               \\
  "\\033[1;47;35m" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\\033[0m"
#define dg(x) debug() << pp1(x)
#define dg1(x) debug() << pp(x)
#define dg2(x, y) debug() << pp(x) pp(y)
#define dg3(x, y, z) debug() << pp(x) pp(y) pp(z)
#define dg4(w, x, y, z) debug() << pp(w) pp(x) pp(y) pp(z)
#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
template <typename T> void db(T x) { debug() << x; }
template <typename T> void db(T x, T y) { debug() << x << " " << y; }
template <typename T> void db(T x, T y, T z) {
  debug() << x << " " << y << " " << z;
}
template <typename T> void db(T x, T y, T z, T a) {
  debug() << x << " " << y << " " << z << " " << a;
}

const int xx = 2e5;
const int Mod = 1e9 + 7;
const int inf = 1e18;
const int Maxn = 20010;
vector<int> can;
void div(int n) {
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      if (n / i == i) {
        can.push_back(i);
      } else {
        can.push_back(i);
        can.push_back(n / i);
      }
    }
  }
  can.push_back(n);
}

int check(int n, int k) {

  while (n % k == 0)
    n /= k;
  if (n % k == 1)
    return 1;
  return 0;
}
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int N;
  cin >> N;

  if (N == 2) {
    cout << 1 << '\\n';
    return 0;
  }
  div(N);
  div(N - 1);
  int ans = 0;
  for (auto i : can) {
    if (check(N, i))
      ans++;
  }
  cout << ans << '\\n';
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string.h>
#include <string>
#include <tuple>
#include <vector>
using namespace std;

#define sim template <class c
#define ris return *this
#define dor > debug &operator<<
#define eni(x)                                                                 \\
  sim > typename enable_if<sizeof dud<c>(0) x 1, debug &>::type operator<<(    \\
            c i) {
sim > struct rge {
  c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni(!=) cerr << boolalpha << i;
  ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c &) { ris; }
#endif
}
;
#define pp(...) "\\033[94m [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\\033[0m"
#define pp1(...)                                                               \\
  "\\033[1;47;35m" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "]\\033[0m"
#define dg(x) debug() << pp1(x)
#define dg1(x) debug() << pp(x)
#define dg2(x, y) debug() << pp(x) pp(y)
#define dg3(x, y, z) debug() << pp(x) pp(y) pp(z)
#define dg4(w, x, y, z) debug() << pp(w) pp(x) pp(y) pp(z)
#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
template <typename T> void db(T x) { debug() << x; }
template <typename T> void db(T x, T y) { debug() << x << " " << y; }
template <typename T> void db(T x, T y, T z) {
  debug() << x << " " << y << " " << z;
}
template <typename T> void db(T x, T y, T z, T a) {
  debug() << x << " " << y << " " << z << " " << a;
}

const int xx = 2e5;
const int Mod = 1e9 + 7;
const int inf = 1e18;
const int Maxn = 20010;
vector<int> can;
void div(int n) {
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      if (n / i == i) {
        can.push_back(i);
      } else {
        can.push_back(i);
        can.push_back(n / i);
      }
    }
  }
  can.push_back(n);
}

int check(int n, int k) {

  while (n % k == 0)
    n /= k;
  if (n % k == 1)
    return 1;
  return 0;
}
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int N;
  cin >> N;
  div(N);
  div(N - 1);
  int ans = 0;
  for (auto i : can) {
    if (check(N, i))
      ans++;
  }
  cout << ans << '\\n';
}