Sorting Algorithms

What Sorting Algorithms covers

Sorting Algorithms is examined in Component 1, Programming and System Development. It covers why a variety of sorting algorithms is needed, bubble sort, insertion sort, quicksort, comparisons, exchanges and passes, storage space and sorting efficiency and writing and altering sort algorithms.

The 7 subtopics

Each one has its own page.

• Why a variety of sorting algorithms is neededRecursive and a non-recursive sorting algorithm, one recursive and one non-recursive sorting algorithm and in-place sort.Open →
• Bubble sortHow a bubble sort works and purpose of a swap flag in a bubble sort.Open →
• Insertion sortGrowing a sorted section from the left by taking the next item and shifting larger ones right, traced item by item, with the comparison counts that follow from it.Open →
• QuicksortHow quicksort works, pivot in quicksort and average and worst case time complexity of quicksort.Open →
• Comparisons, exchanges and passesComparison in a sorting algorithm, exchange in a sorting algorithm and pass through the data.Open →
• Storage space and sorting efficiencySpace complexity of a sorting algorithm, space complexity of bubble sort and insertion sort and space complexity of quicksort and explain where the space goes.Open →
• Writing and altering sort algorithmsChanging a working sort rather than writing one from nothing: reversing the order, sorting records on one field, and adding the swap flag that stops a bubble sort early.Open →

What you need to know

Answer each one before you reveal it.

Take Sorting Algorithms further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Time complexity vs Space complexity

  Time complexity: counting operations as data grows. Space complexity: counting extra memory.

• Pass vs Comparison

  Pass: one whole sweep of the list. Comparison: a single test inside it.

• Comparison vs Exchange

  Comparison: an operation that only reads two values. Exchange: an operation that writes three times to swap two values.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Why does more than one sorting algorithm exist?

   Model answer

   Each algorithm is fastest in different circumstances, so none is best for every situation. The choice depends on the size of the data, how nearly sorted it is and the memory available.

2. 2

   Give two properties of a data set that influence which sort should be used.

   Model answer

   The number of items and how nearly sorted they already are both matter. The amount of spare memory available is a third factor.

3. 3

   Which sorting algorithm suits a small list that is already nearly in order?

   Model answer

   Insertion sort suits nearly sorted data because few items have to move. The algorithm approaches O(n) on such a list.

4. 4

   Which sorting algorithm is generally chosen for a large unordered list held in memory?

   Model answer

   Quicksort is generally chosen because its average performance is O(n log n). The algorithm also sorts in place and needs little extra memory.

5. 5

   Distinguish between a recursive and a non-recursive sorting algorithm.

   Model answer

   A recursive sort calls itself on smaller parts of the data, as quicksort does. A non-recursive sort uses loops only, as bubble sort and insertion sort do.

6. 6

   Name one recursive and one non-recursive sorting algorithm.

   Model answer

   Quicksort is a recursive sorting algorithm. Bubble sort is a non-recursive sorting algorithm.

What is inside Levo

Six ways to work the same material.

Sorting Algorithms revision questions

What does Sorting Algorithms cover in Eduqas A-Level Computer Science?

7 subtopics: why a variety of sorting algorithms is needed, bubble sort, insertion sort, quicksort, comparisons, exchanges and passes, storage space and sorting efficiency and writing and altering sort algorithms. Each one has its own page with questions and model answers.

How is Sorting Algorithms organised?

By the Eduqas A500QS specification, subtopic by subtopic, so it matches the order you are taught it in.