// ****************************************************************
//   PowersOf2.java
//
//   Print out as many powers of 2 as the user requests
//
// ****************************************************************
import java.util.Scanner;

public class PowersOf2
{
    public static void main(String[] args)
    {
        int numPowersOf2;        //How many powers of 2 to compute
        int nextPowerOf2 = 1;    //Current power of  2
        int exponent = 0;        //Exponent for current power of 2 -- this
                        	      //also serves as a counter for the loop
        Scanner scan = new Scanner(System.in);

        System.out.println("How many powers of 2 would you like printed?");
        numPowersOf2 = scan.nextInt();

        //print a message saying how many powers of 2 will be printed
        System.out.println("Okay, I will print " + numPowersOf2 + " powers of two.");


	  do
        {
	      //print out current power of 2
         System.out.println(2 + "^" + exponent + " = " + nextPowerOf2);

         //find next power of 2 -- how do you get this from the last one?
         nextPowerOf2 *= 2;

         //increment exponent
         exponent += 1;

	  } while (exponent != numPowersOf2);
    }
}