Recursive function, which writes integer digits in an array(vector) in C++?

Question

I have a C++ program, in which I have to create a recursive function that writes all the digits of a given positive integer in an array - in this case a vector. However, when I compile the program and enter a number, it stops working. I want to ask why this happens?

    #include <iostream>
    #include <vector>
    using namespace std;
    vector <int> arr;
    int temp;
    int fill_Array(int num)
    {
        if(num>=1 && num<=9)
        {
            arr.push_back(num);
        }

        temp = fill_Array(num)%10;
        arr.push_back(temp);
        num/=10;

    }
    int main()
    {
        int n;
        cin>>n;
        fill_Array(n);
        for(int i=0; i<arr.size(); i++)
        {
            cout<<arr[i]<<endl;
        }

        return 0;
    }

Answer 1

In the given code, recursion function does not returning any value, so return type for that function have no use. calling the function for recursion is in the wrong place. Correct code given below:

#include <iostream>
#include <vector>
using namespace std;
vector <int> arr;
int temp;
void fill_Array(int num)
{
    if(num>=1 && num<=9)
    {
        arr.push_back(num);
    }
    else{
        temp = num%10;
        arr.push_back(temp);
        fill_Array(num/=10);
    }
}
int main()
{
    int n;
    cin>>n;
    fill_Array(n);
    for(int i=0; i<arr.size(); i++)
    {
        cout<<arr[i]<<endl;
    }

    return 0;
}