Algorithms — FAQ

Linear Search has two main advantages in certain situations. Firstly, it does not require the data to be sorted, which is a significant pre-requisite for Binary Search. Sorting a list takes time, and if you only need to search the list once, it might be faster overall to just do a linear search. Secondly, it is very simple to implement.

Yes, many. Bubble Sort is taught because it is simple to understand, but its $O(n^2)$ time complexity makes it very inefficient for large lists. More advanced algorithms like Merge Sort and Quick Sort have an average time complexity of $O(n \log n)$, making them vastly superior for practical use.

No, you should not use a specific programming language like Python or Java unless explicitly asked. The standard ways to express an algorithm are through structured English, flowcharts, or, most commonly, pseudocode. The Cambridge syllabus provides a standard for pseudocode that you should learn and use.

Worst-case complexity ($O$) describes the maximum number of steps an algorithm might take for a given input size 'n'. For a linear search, this is finding the item at the very end. Average-case describes the expected performance across all possible inputs. While both are important, A-Level focuses primarily on understanding and comparing worst-case complexities.