Problem URL: Pow(x, n)

We will follow divide and conquar method to solve the problems. We we divide the n until it's a single digit, then the muliplication result is the number itself. When we merge it, we will join the numbers by multiply themselves. If the input n is negetaive, then we just divide 1 by the result.

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

            res = helper(x * x, n // 2)
            return x * res if n % 2 else res

        res = helper(x, abs(n))
        return res if n >= 0 else 1 / res

Time Complexity: O(log(n))
Space Complexity: O(n)