"""
https://leetcode.com/problems/powx-n/

Implement pow(x, n), which calculates x raised to the power n (xn).

Example 1:

Input: 2.00000, 10
Output: 1024.00000
Example 2:

Input: 2.10000, 3
Output: 9.26100
Example 3:

Input: 2.00000, -2
Output: 0.25000
Explanation: 2-2 = 1/22 = 1/4 = 0.25

Note:
-100.0 < x < 100.0
n is a 32-bit signed integer, within the range [−231, 231 − 1]

"""


class Solution:
    def myPow(self, x: float, n: int) -> float:
        if n < 0:
            x = 1 / x
            n = -n

        ans = 1
        tmp = x

        while n != 0:
            if n % 2 == 1:
                ans *= tmp
            tmp *= tmp
            n //= 2
        return ans