Given an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. If target exists, return its index. Otherwise, return -1.
You must write an algorithm with O(log n) runtime complexity.
9 exists in nums and its index is 4.
2 does not exist in nums so return -1.
1 ≤ nums.length ≤ 10⁴-10⁴ < nums[i], target < 10⁴nums are unique.nums is sorted in ascending order.Maintain left and right pointers, check the midpoint each time.
4