/* Hail.java
 * 
 * This program generates a Hailstone series based on user input, 
 * determines number of items in that series, and finally displays
 * the largest value seen.
 * 
 */

import tio.*;

public class Hail {

  public static void main(String args[]) {

	long	hailval=0,	// hailstone value holder
		count=0,	// counter
		largest=0,	// holds largest seen so far
		init=0;	// remembers initial value
	
	System.out.println("Welcome to the Hailstone program.");
	System.out.print("Please enter the initial value: ");
	init = Console.in.readInt();

	while (init <= 0) {
		System.out.print("Please enter a positive number: ");
		init = Console.in.readInt();
	}

	count = 1;		// we've seen one number
	largest = init;	// it is the largest so far
	hailval = init;	// and we begin with the initial value
	
	while ( hailval != 4  &&  hailval !=2  &&  hailval != 1) {

  		// get next value
		if (hailval % 2 == 0)
			hailval /= 2;
		else
			hailval = hailval*3 + 1;

		// increment counter
		count++;

		// check for largest
		if (hailval > largest)
			largest = hailval;
		
		// uncomment to see sequence on screen
		// System.out.println(hailval);
	
	}//end while

	System.out.println("For the sequence starting at: " + init);
	System.out.print("There were " + count + " items and ");
	System.out.println(largest + " was the largest.");

  }//end main()
}//end class
// end Hail.java


/* SAMPLE OUTPUT
 *
$ java Hail
Welcome to the Hailstone program.
Please enter the initial value: 17
For the sequence starting at: 17
There were 11 items and 52 was the largest.
$ java Hail
Welcome to the Hailstone program.
Please enter the initial value: 101
For the sequence starting at: 101
There were 24 items and 304 was the largest.
$ java Hail
Welcome to the Hailstone program.
Please enter the initial value: 531
For the sequence starting at: 531
There were 122 items and 9232 was the largest.
$

*/