Search_in_rotated_sorted_array.py

# There is an integer array nums sorted in ascending order (with distinct values).

# Prior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1 <= k < nums.length) such that the resulting array
# is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,5,6,7] might be rotated at pivot index 
# 3 and become [4,5,6,7,0,1,2].

# Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.

# You must write an algorithm with O(log n) runtime complexity.
# 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:
        left = 0
        right = len(nums)-1
        
        while left <= right:
            mid = (left + right)//2
            if nums[mid] == target:
                return mid
            if nums[left] <= nums[mid]:
                if target >= nums[left] and target <= nums[mid]:
                    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