Search in Rotated Sorted Array - Python Leetcode

 You are given an integer array nums sorted in ascending order, and an integer target.

Suppose that nums is rotated at some pivot unknown to you beforehand (i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).

If target is found in the array return its index, otherwise, return -1.

 

Example 1:

Input: nums = [4,5,6,7,0,1,2], target = 0
Output: 4

Example 2:

Input: nums = [4,5,6,7,0,1,2], target = 3
Output: -1

Example 3:

Input: nums = [1], target = 0
Output: -1

class Solution:
    def search(self, nums: List[int], target: int) -> int:
        if not nums:
            return -1
        
        if len(nums) == 1 and target == nums[0]:
            return 0
        
        left = 0
        right = len(nums)-1
        
        while left <= right:
            mid = left + (right-left) // 2
            
            if nums[mid] == target:
                return mid
            
            elif nums[mid] >= nums[left]:
                if target < nums[mid] and target >= nums[left]:
                    right = mid - 1
                else:
                    left = mid + 1
            else:
                if target > nums[mid] and target <= nums[right]:
                    left = mid + 1
                else:
                    right = mid - 1
        return -1
        

Complexity Analysis
Time complexity: $\mathcal{O}(\log{N})$.
Space complexity: $\mathcal{O}(1)$.