Binary Search 15 XP Easy

Now implement the classic binary search yourself from scratch. Given a sorted array and a target, return the index or -1.

Remember the three steps inside the loop:

• Compute mid = (left + right) // 2
• If nums[mid] == target, return mid
• If nums[mid] < target, search right: left = mid + 1
• If nums[mid] > target, search left: right = mid - 1

Time: O(log n) — for 1 million elements, at most ~20 comparisons!