33.py

# 33. Search in Rotated Sorted Array
# 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, target):
        low = 0
        high = len(nums) - 1
        while low <= high:
            mid = (low + high) // 2
            if nums[mid] == target:
                return mid
            if nums[low] <= mid:
                if nums[low] < target < nums[mid]:
                    high = mid - 1
                else:
                    low = mid + 1
            else:
                if nums[mid] < target <= nums[high]:
                    low = mid + 1
                else:
                    high = mid - 1
        return -1

solution = Solution()
result = solution.search([4,5,6,7,0,1,2], 0)
print(result)