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Homework Help: Creating pow in java

  1. Jan 18, 2009 #1
    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. jcsd
  3. Jan 19, 2009 #2

    Dick

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  4. Jan 19, 2009 #3
    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.
     
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