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

Prior to being passed to your function, nums is rotated at an unknown pivot index k (0 <= 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 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:

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

Solution: Simply binary search