Question

I have an assignment to write a recursive function that writes the digits of a positive integer in reverse order. My problem is that the function doesn’t display the reverse correctly. I know im supposed to use % or 10 when displaying the number and / of 10 when in the recursive call as well as the base case is supposed to be < 10. Here is my code.

#include <iostream>
using namespace std;

int reverse(int,int);

int main()
{
    int number;
    int n;

    cout << " Enter number to reverse." << endl;
    cin >> number;
    cout << reverse(number % 10,0);

    return 0;
}//end main

int reverse(int number,int n)
{

    if(n < 10)
    {
        return n;
    }
    else
    {
        return reverse(number/10,n);
    }
}// end reverse

Answer 1

I think this is what your function should be:

void reverse(int number){
    if(number == 0) //base/basic case i.e if number is zero the problem is already solved, nothing to do, so simply return
        return;
    else{
        cout << number % 10; // print that last digit, e.g 103%10 == 3 
        reverse(number/10); //solve the same problem but with smaller number, i.e make the problem smaller by dividing it by 10,  initially we had 103, now 10 
    }
}