FAIL

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <vector>
#include <set>

using namespace std;

bool number_unique(set<int> &ls, int number){

    // very bad

    bool is_in = ls.find(number) != ls.end();

    if(is_in){
        return false;
    } else {
        return true;
    }
}

void fillSet(vector<int> &usergen, set<int> &array, size_t max = 6){

    if(usergen.size() > 0) {
        // end of usergen
        array.insert(usergen.back());
        usergen.pop_back();
    }

    int number = (rand() % 49) + 1;

    if(number_unique(array, number))
        array.insert(number);

    if(array.size() < max) {
        fillSet(usergen, array, max);
    }
}

int main(){

     srand( time( NULL ) );

     set<int> notAllowed, winning;

     for(int i = 0; i < 5; i++){
        notAllowed.insert(i);
     }

}