Single Element in a Sorted Array

Medium

Given a sorted array nums where every element appears exactly twice except for one element that appears exactly once, return the single element. Your solution must run in O(log n) time and O(1) space.

Example 1

Input:  nums = [1,1,2,3,3,4,4,8,8]
Output: 2

Example 2

Input:  nums = [3,3,7,7,10,11,11]
Output: 10

Example 3

Input:  nums = [1]
Output: 1

Constraints

• 1 <= nums.length <= 10^5
• 0 <= nums[i] <= 10^5
• Every element appears twice except one which appears once.