Leetcode: Pow(x, n) @Python

class Solution:
    # @param x, a float
    # @param n, a integer
    # @return a float
    def pow(self, x, n):
        if n==0:
            return 1
        elif n==1:
            return x
        elif n%2==0:
            return pow(x*x,n/2)
        else:
            return pow(x*x,n/2)*x