Solution:

#include <iostream>

using namespace std;

//////////  Recursive function/////////

long long rec_factorial(int n)
{
    if(n==0)
    {
        return 1;
    }
    return n*rec_factorial(n-1);
}

/////////////Iterative function///////

int fact(int n)
{
    int ans=1;
    for(int i=1;i<=n;i++)
    {
        ans*=i;
    }
    return ans;
}

int main()
{
    cout<<rec_factorial(6)<<endl;
    cout<<fact(9)<<endl;

    return 0;
}