This program computes the power of a number by recursion. That is it calculates x^n (x raised to teh power n) for a positive integer n and a positive integer x.
/* Power of a number by recursion
Write a recursive mathematical definition for computing x^n for a positive integer n
and a positive integer x.
E.g. Computer x ^ n by recursion
Mukesh Tekwani
*/
import java.util.Scanner;
class PowerofN
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.print("Enter the number x:");
int x = input.nextInt();
System.out.print("Enter the power of x:");
int n = input.nextInt();
//take care of mischief by user
if (x < 0)
x = -x;
if (n < 0)
n = -n;
System.out.println(x + " raised to " + n + " is " + power(x, n));
}
public static long power(int x, int n)
{
if (n == 0) //base case
return 1;
else if (n == 1)
return x;
else
return (x * power(x, n - 1));
}
}