Lukujono

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll rec(ll n) {
  static unordered_map<ll, ll> C;
  if (auto it = C.find(n); it != C.end()) {
    return it->second;
  }
  if (n <= 1) {
    return n;
  }
  ll &s = C[n];
  for (int i = 1; i * i <= n; ++i) {
    if (i > 1 && n / i != i) {
      s += rec(n / i);
    }
    ll k = n / i - (n / (i + 1) + 1) + 1;
    if (k > 0) s += rec(i) * k;
  }
  return s;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  ll n;
  cin >> n;
  cout << rec(n) << endl;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 1

Verdict: ACCEPTED

Test 7

Group: 1

Verdict: ACCEPTED

Test 8

Group: 1

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 2

Verdict: ACCEPTED

Test 16

Group: 2

Verdict: ACCEPTED

Test 17

Group: 3

Verdict: ACCEPTED

Test 18

Group: 3

Verdict: ACCEPTED

Test 19

Group: 3

Verdict: ACCEPTED

Test 20

Group: 3

Verdict: ACCEPTED

Test 21

Group: 3

Verdict: ACCEPTED

Test 22

Group: 3

Verdict: ACCEPTED

Test 23

Group: 3

Verdict: ACCEPTED

Test 24

Group: 3

Verdict: ACCEPTED