3n+1 Problem: PC/UVa IDs: 110101/100

hailstorm.java

	
/*
 * Main.java
 *  java program model for www.programming-challenges.com
 */

import java.io.*;
import java.util.*;

class hailstorm implements Runnable{

    public static void main(String args[])  // entry point from OS
    {
    	hailstorm myWork = new hailstorm();  // Construct the bootloader
        myWork.run();            // execute
    }

    public void run() {
        new myStuff().run();
    }
}
class myStuff implements Runnable{
	
	int maxSequenceLength(long start, long end)
	{
		if (start > end) 
		{
			long temp;
			temp = start;
			start = end;
			end = temp;			
		}
		int max_count = 0;
		for (long i=start; i <= end; i++)
		{	
			long num = i;
			long count = 1;
			while (num != 1)
			{
				if (num%2 == 0)
					num = num/2;
				else
					num = 3*num+1;
				
				count++;
			}
			if (count > max_count)
				max_count = (int)count;
				
		}
		return max_count;
	};
	
    public void run(){
		try 
		{
			BufferedReader is = new BufferedReader(new InputStreamReader(System.in));
			String inputLine;
			while ((inputLine = is.readLine( )) != null) {
				
				String a[] = inputLine.trim().split("\\s+");
				
				System.out.printf("%d %d %d\n",Integer.parseInt(a[0]),Integer.parseInt(a[1]),
									maxSequenceLength(Integer.parseInt(a[0]),Integer.parseInt(a[1])));
			}
			is.close( );
		} catch (Exception e) {
//			System.out.println(e);
		}
    }
    
}