Question

I am preparing for my interview tomorrow — I need the answer to this question:

How can you print 1 to 10 & 10 to 1 by using recursion with single variable

Answer 1

I’m going to get downvoted I just know it but here is (a) solution. Not the best one but you should be able to make it better yourself.

class Program
{
    static void Main(string[] args)
    {
        printNumDown(10);
    }

    static void printNumDown(int num)
    {
        Console.WriteLine(num.ToString());
        if (num > 1)
            printNumDown(num - 1);
        else
            printNumUp(num + 1);
    }

    static void printNumUp(int num)
    {
        Console.WriteLine(num.ToString());
        if (num < 10)
            printNumUp(num + 1);
    }
}