Recursion

Programming languages allow the usage of certain mechanisms to simplify solving a problem. Recursion is one of those mechanisms. It is the ability of a method to call itself. When properly designed, a recursive method can simplify the way a solution to a certain problem is expressed using code.

Classic examples in recursion include the computation of the factorial of a number or the sorting of an array of numbers. For the sake of simplicity, we are going to look at the first case: finding the factorial of a number.

class Example11 {
    public static long fact ( int n ) {
        if ( n == 0 ) return 1;
        return n * fact ( n – 1 );
    }
    public static void main(String[] args) {
        int input = Integer.parseInt(args[0]);
        long...