Homework Help: Creating pow in java

1. Jan 18, 2009

cgrumiea

1. The problem statement, all variables and given/known data
Define a recursive method named pow that takes two integers, x and n, and returns the result of raising x to the n-th power. Assume that n is non-negative.

pow(5, 0) ==> 1
pow(2, 10) ==> 1024
pow(-3, 2) ==> 9

2. Relevant equations

3. The attempt at a solution
I'm totally fresh to java, and am not used to or comfortable with recursion.
public static int pow(int x, int n) {

I don't know what to do. Should I have some increasing value to count up to when x has been multiplied by itself n times? I know scheme which seems to be a bit of a different ball game here. Any help would be appreciated.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 19, 2009

Dick

pow(n,k)=pow(n,k-1)*n, isn't it? pow(n,0)=1. Isn't that a pretty recipe for recursion? You don't have to count anything at all.

3. Jan 19, 2009

gendou2

yep, and remember to check the base case first:
Code (Text):
if(k==1) return n;
or:
Code (Text):
if(k==0) return 1;
if you will.