// CSE 143, Winter 2010, Marty Stepp
//
// This file contains two recursive methods that we wrote in class.

public class Stars {
    public static void main(String[] args) {
        printStars(9);
        printStars(4);
        printStars(17);

        System.out.println("5! is " + factorial(5));
        System.out.println("11! is " + factorial(11));
    }
    
    // Returns n factorial, defined as the product from 1 to n.
    // Precondition: n >= 0
    public static int factorial(int n) {
        if (n == 0) {
            // base case
            return 1;
        } else {
            // recursive case
            // 5! = 1 * 2 * 3 * 4 * 5
            // 5! = 5 * 4!
            //        = 4 * 3!
            return n * factorial(n - 1);
        }
    }
    
    // Prints a line of n stars (a blank line if n == 0).
    // Precondition: n >= 0
    public static void printStars(int n) {
        if (n == 0) {
            // base case
            System.out.println();
        } else {
            // recursive case
            System.out.print("*");
            printStars(n - 1);
        }
    }
}