What is Linear Search?

• A. A sequential search through a list until a list item is found.
• B. A binary search on a sorted array.
• C. A method to hash data into buckets.
• D. A technique to traverse a tree in-order.

Answer: (C)

Linear search is a simple technique for finding an element by checking each item in a list one by one until you find a match or reach the end. It works on unsorted data and doesn’t require any special structure. If the target is the first item, you stop immediately; if it’s near the end or not present, you may end up checking every element. Its time grows linearly with the size of the list, giving O(n) in the worst and average cases and O(1) in the best case when the first element is a match. This approach is handy for small lists or when you don’t want to maintain order or use additional data structures. The other descriptions refer to different techniques: hashing maps values to buckets for quick lookup, binary search requires a sorted array and halves the search space each time, and in-order traversal is a way to visit nodes in a binary tree. Linear search, by contrast, performs a straightforward, sequential scan.