// Helene Martin, CSE 142
// Short problems with interesting twists.
// Always start by asking yourself how you would solve the problem by hand.
// What programming tools would allow you to automate that?

public class ReviewProblems {
	public static void main(String[] args) {
		showTwos(128);
		System.out.println(stutter("hello"));
	}
	
	/* Write a method named showTwos that shows the factors of 2 in an integer.  For example:
	Call 				Output
	showTwos(7); 	7 = 7
	showTwos(18); 	18 = 2 * 9
	showTwos(68); 	68 = 2 * 2 * 17
	showTwos(120); 120 = 2 * 2 * 2 * 15
	
	The idea is to express the number as a product of factors of 2 and an odd number.  The number 120 has 3 
	factors of 2 multiplied by the odd number 15.  For odd numbers (e.g. 7), there are no factors of 2, so you just 
	show the number itself.  Assume that your method is passed a number greater than 0.
	*/
	
	public static void showTwos(int num) {
		System.out.print(num + " = ");
		while (num % 2 == 0) {
			System.out.print("2 * ");
			num = num / 2;
		}
		System.out.println(num);
	}
	
	// Write a method called digitSum that takes an integer n as a parameter
	// and that returns the sum of the digits of n.  Assume that n is >= 0.
	
	// Write a method called stutter that takes a string as a parameter and
	// that returns a new string where each letter of the original string has
	// been replaced with two of that letter.  For example, stutter("hello")
	// should return "hheelllloo"
	
	public static String stutter(String s) {
		String result = "";
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			result = result + c + c;
		}
		return result;
	}

	// On your own for practice:
	// Write a method called noSpaces that takes a String as a parameter and
	// that returns a new string that contains the nonspace characters of the
	// original.  For example, noSpaces("how are you?")  should return
 	// "howareyou?"
}