751 Ciekawa Wyliczanka

#include <iostream>
#include <cmath>
#include <vector>

using namespace std;

vector <int> numbers;

void to_binary(int n)
{
    if(n/2 != 0)
    {
        to_binary(n/2);
    }

    if(n%2 == 0)
    {
        numbers.push_back(5);
    }
    else
        numbers.push_back(6);

}

int main()
{
    int S = 0;
    int k;
    int n = 0;
    int i = 1;
    cin >> k;
    while(S < k)
    {
        S = S + pow(2,i);
        n++;
        i++;
    }
    int temp = (pow(2, n) - (S-k)) - 1;
    //cout << temp << endl;
    //cout << n << endl << endl;
    to_binary(temp);
    int* tablica = new int[n];
    for(int i = 0; i < n; ++i)
    {
        tablica[i] = 5;
    }

    for(int i = 0; i < numbers.size(); ++i)
    {
        tablica[i] = numbers[i];
    }

    for(int i = 0; i < n; ++i)
    {
        cout << tablica[i];
    }
}