3n+1

Problem_100.java

import java.util.Arrays;
import java.util.Scanner;
import static java.lang.System.out;

/**
 * mistake: never read question properly. we need to calculate i upto and including j. 
 * hence for(; i<= j; i++) not for(; i< j; i++)
 * the latter is done out of habbit =/
 */
public class Main {

  //Start 1236 
	//+ 15 mins to reading questions 
	public static void main(String[] args) {
	
				
		 Scanner in = new Scanner(System.in);
    	 while(in.hasNext()) {
    		 
    		 int i = in.nextInt();
    		 int j = in.nextInt();
    		 int _i = i;
    		 int _j = j; 
    		 
    		 
    		 int tmp; 
    		 if( i > j ) {
    			 tmp = i;
    			 i = j;
    			 j = tmp;
    		 }
    		 
    		  
    		 int max = 0;
    		 
    		 for(; i<=j; i++) {
    			 
    			 int count = 0;
    			 
    			 int n = i;
    			 while(n != 1) {
        			 //out.print(n + "," );
        			 
        			 if(n % 2 != 0 )
        				 n = 3*n+1;
        			 else
        				 n = n/2;
        			 
        			 count++; 
        			 max = Math.max(max, count);
        		 }
    		 }
    		 
    		 
    		 //System.out.println("");
    		 System.out.println(_i + " " + _j + " " + (max+1));
    		 //System.out.println("\n------------");
    		 
    		 
    	 }
		
		
		
	}//end of void main 
}//end of class main