Given a sorted array of integers nums and an integer target, return the index of target if it exists in the array, or -1 if it does not exist. You must write an algorithm with O(log n) runtime complexity.
Input: A sorted integer array nums and an integer target.
Output: Return the index of target in nums, or -1 if not found.
Input: [1,3,5,7,9,11], 7
Output: 3
Explanation: nums[3] = 7. Binary search: lo=0,hi=5 → mid=2(5<7)→lo=3, mid=4(9>7)→hi=3, mid=3(7==7)→return 3.Input: [2,4,6,8,10], 5
Output: -1
Explanation: 5 is not in the array. Binary search exhausts all possibilities and returns -1.Input: [-10,-5,0,5,10], -5
Output: 1
Explanation: nums[1] = -5. mid=2(0>-5)→hi=1, mid=0(-10<-5)→lo=1, mid=1(-5==-5)→return 1.1 <= nums.length <= 10^4-10^9 <= nums[i] <= 10^9nums is sorted in ascending order-10^9 <= target <= 10^9All values in nums are unique