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Pow(x, n)

Problem Statement​

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

Leetcode Link

Example 1:​

Input: x = 2.00000, n = 10
Output: 1024.00000

Example 2:​

Input: x = 2.10000, n = 3
Output: 9.26100

Example 3:​

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

Constraints:​

  • -100.0 < x < 100.0
  • -231 <= n <= 231-1
  • n is an integer.
  • -104 <= xn <= 104

Code​

Python Code
class Solution:
    # @param {float} x
    # @param {integer} n
    # @return {float}
    def myPow(self, x, n):
        if n < 0:
            return 1 / self.pow(x, -n)
        else:
            return self.pow(x, n)

    def pow(self, x, n):
        if n == 0:
            return 1

        temp = self.pow(x, n / 2)
        if n % 2 == 0:
            return temp * temp
        else:
            return temp * temp * x