Program to calculate reverse of a number in C++.

Solution:

#include <iostream>

using namespace std;

int rev(int n)
{
    static int r=0;
    if(n==0)
        return r;
    else
    {
        r=(r*10)+n%10;
        return rev(n/10);
    }
}
 
int main()
{
    int n,ans;
    cout<<"Enter a number ";
    cin>>n;
    ans = rev(n);
    cout << "Reverse of  "<< n<<" is "<<ans;
    return 0;
}

Output :

Enter a number 123
Reverse of  123 is 321