Дано натуральное число найти произведение нечетных цифр числа

#include <iostream>
 
int main()
{
    int num = 0;
    std::cout << "Enter number from 1000 to " << INT_MAX << " - ";
    std::cin >> num;
    int result_i = 1;
    bool result_b = false;
    while(num)
    {
        int temp = num % 10;
        num /= 10;
        if (temp % 2 != 0)
            result_i *= temp;
        if (temp % 3 == 0)
            result_b = true;
    }
 
    std::cout << "\nResult - " << result_i;
    std::cout << "\nIs there any number, divided on three with no remainder of the division? \n(1 - true, 0 - false) - " << result_b;
 
    system("pause>>null");
}

#include <iostream>
using namespace std;
typedef unsigned long long int ull;
 
int main() {
    auto f = [](ull n, int i, int a, int b, const auto& la) -> int {
        return n ? la(n/10, i+1, (i&1 ? n%10 : 1)*a, (!(i&1) ? n%10 : 1)*b, la) : i&1 ? b : a;};
        
    auto g = [](ull n, const auto& la) -> bool {return n ? (n%10%3) && la(n/10, la) : true;};
 
    ull n; cout<<"Input n: "; cin>>n;
    cout<<"Product of odd digits = "; cout<<f(n, 0, 1, 1, f)<<'\n';
    cout<<"All digits are not divided by 3 = "; cout<<g(n, g)<<'\n';
    return 0;
}