Lukujono

#include <iostream>
#include <unordered_map>
#include <algorithm>
#include <cassert>

using namespace std;
int x = 0;

int64_t solve(int i)
{
	static unordered_map<int, int64_t> cache;

	if(cache.count(i))
		return cache[i];

	if(i == 0 || i == 1)
		return i;

	int64_t r = 0;
	
	for(int64_t monta = 1; monta <= i / 2;)
	{
		int64_t suurin = i / monta;
		int64_t pienin = i / (monta + 1) + 1;
		int64_t kertaa = suurin - pienin + 1;

		if(i == x)
			cout << kertaa << " * solve " << monta << endl;


		r += kertaa * solve(monta);

		int64_t a, b;
		a = monta;
		b = i / 2 + 2;

		while(a < b)
		{
			int64_t c = (a + b) / 2;
			int64_t res = i / c;

			if(res + 1 < pienin)
			{
				b = c;
			}
			else
			{
				a = c + 1;
			}
		}

		//cout << monta << endl;

		monta = b - 1;

		//cout << i << " " << pienin << " " << monta << endl;
	}

	return cache[i] = r;
}

int main()
{
	int n;
	cin >> n;
	cout << solve(n) << endl;

	/*for(x = 2; x < 20; x++)
	{
		cout << "X: " << x << endl;
		solve(x);
		cout << 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: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 21

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 22

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 23

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 24

Group: 3

Verdict: TIME LIMIT EXCEEDED