import java.util.Scanner;
import java.util.StringTokenizer;

/** Formula3.java -- Let's illustrate recursive formulas for exponentiation
 *  and Pascal's triangle.
 */
public class Formula3
{
  public static void main(String [] args)
  {
    System.out.print("Enter two positive integers:  ");
    Scanner kbd = new Scanner(System.in);
    String line = kbd.nextLine();
    StringTokenizer tok = new StringTokenizer(line, ", ");
    int a = Integer.parseInt(tok.nextToken());
    int b = Integer.parseInt(tok.nextToken());

    int expValue = exp(a, b);
    System.out.printf("%d to the %d is %d\n", a, b, expValue);

    int pascalValue = pascal(a, b);
    System.out.printf("Number on row %d col %d of Pascal's triangle = %d\n",
		      a, b, pascalValue);
  }

  public static int exp(int a, int b)
  {
    if (b == 0)
    {
      return 1;
    }
    else if (b % 2 == 0)
    {
      int returnValue = exp(a, b/2);
      return returnValue * returnValue;
    }
    else
    {
      int returnValue = exp(a, b-1);
      return a * returnValue;
    }
  }

  public static int pascal(int a, int b)
  {
    if (a == b || b == 0)
    {
      return 1;
    }
    else if (b > a)
    {
      return 0;
    }
    else
    {
      return pascal(a-1, b-1) + pascal(a-1,b);
    }
  }
}