- Given an array of integers
numswhich is sorted in ascending order, and an integer
target, write a function to search
targetexists, then return its index. Otherwise, return
- You must write an algorithm with
O(log n)runtime complexity.
- This challenge corresponds to LeetCode #704.
1 <= nums.length <= 104
-104 < nums[i], target < 104
- All the integers in
numsis sorted in ascending order.
Input: nums = [-1, 0, 3, 5, 9, 12], target = 9 Output: 4 Explanation: 9 exists in nums and its index is 4
Input: nums = [-1, 0, 3, 5, 9, 12], target = 2 Output: -1 Explanation: 2 does not exist in nums so return -1
Input: head =  Output: 
Below is my solution and some test cases. This solution has a logarithmic time complexity O(log n) and a constant space complexity O(1), where n is the length of the input list.