50 Pow(x, n)

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

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/(2^2) = 1/4 = 0.25

Constraints:

  • -100.0 < x < 100.0
  • -231 <= n <= 231-1
  • -104 <= xn <= 104
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class Solution:
    def myPow(self, x: float, n: int) -> float:
        if n == 0:
            return 1
        if n < 0:
            return self.myPow(1 / x, -n)
        res = self.myPow(x * x, n // 2)
        if n % 2 == 1:
            res *= x
        return res
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func myPow(x float64, n int) float64 {
    if n == 0 {
        return 1
    }
    if n < 0 {
        return myPow(1/x, -n)
    }
    result := myPow(x*x, n/2)
    if n % 2 == 1 {
        result *= x
    }
    return result
}