[Leetcode][python]Pow(x, n)

class Solution(object):
    def myPow(self, x, n):
        """
        :type x: float
        :type n: int
        :rtype: float
        """
        if n == 0:
            return 1.0  # 返回float 
        elif n < 0:
            return 1 / self.myPow(x, -n)
        elif n % 2: # 结果为1，奇数
            return self.myPow(x*x,n/2)*x
        else: # 偶数
            return self.myPow(x*x,n/2)