Algorithms Worksheet - GCSE - Intermediate
Algorithms worksheet for Key Stage 4 / GCSE (Ages 14-16). Intermediate level computing practice, aligned to the UK National Curriculum. Print-ready with answer key included.
Exploring Algorithms in Computing
Key Stage 4 / GCSE (Ages 14-16) - Intermediate Level
Instructions: This worksheet will guide you through various algorithm-related tasks, focusing on understanding and applying key concepts in computing. Follow the instructions for each activity carefully and use the provided answer spaces to record your responses.
Understanding Sorting Algorithms
Review the characteristics of different sorting algorithms. Then, answer the questions based on the table below. Consider the time complexity and use cases for each algorithm.
| Algorithm | Time Complexity | Use Case |
| Bubble Sort | O(n²) | Small datasets |
| Merge Sort | O(n log n) | Large datasets |
| Insertion Sort | O(n²) | Nearly sorted datasets |
| Quick Sort | O(n log n) | General purpose |
1. Which algorithm is most efficient for large datasets?
2. What is the time complexity of Bubble Sort?
3. Which algorithm is best for nearly sorted datasets?
Binary Search Algorithm
Binary search is an efficient algorithm for finding an item from a sorted list of items. Describe how binary search works and outline its advantages over linear search.
Explain the process of binary search and its advantages over linear search. [6 marks]
Algorithm Efficiency
Consider the following algorithms and their Big O notation. Match each algorithm with its correct time complexity.
1. Linear Search --- O(n)
2. Binary Search --- O(log n)
3. Bubble Sort --- O(n²)
4. Merge Sort --- O(n log n)
Algorithm Design: Pseudocode
Write pseudocode for a simple algorithm that finds the maximum value in a list of integers. Ensure your pseudocode is clear and logically structured.
Write pseudocode to find the maximum value in a list of integers. [8 marks]
Comparing Search Algorithms
Analyse the following table comparing linear and binary search algorithms. Use the information to answer the questions below.
| Feature | Linear Search | Binary Search |
| Time Complexity | O(n) | O(log n) |
| Data Requirement | Unsorted | Sorted |
1. Which search algorithm requires sorted data?
2. What is the time complexity of Binary Search?
Practical Application of Algorithms
Describe a real-world scenario where a sorting algorithm is used. Explain why a particular algorithm is chosen for this scenario.
Describe a real-world scenario where a sorting algorithm is applied and justify the choice of algorithm. [10 marks]
Algorithm Analysis
Consider the following pseudocode for a simple algorithm. Identify its time complexity and explain your reasoning.
Pseudocode:
FOR i = 1 TO n
FOR j = 1 TO n
PRINT i, j
Identify the time complexity and explain why. [5 marks]
Algorithm Efficiency in Practice
Reflect on the importance of algorithm efficiency in software development. Discuss how inefficient algorithms can impact software performance.
Discuss the impact of inefficient algorithms on software performance. [8 marks]
Activity 1: Merge Sort ; O(n²) ; Insertion Sort
Activity 2: Binary search divides the list and compares the middle element; it is faster than linear search for large, sorted datasets.
Activity 3: 1. O(n) ; 2. O(log n) ; 3. O(n²) ; 4. O(n log n)
Activity 4: Pseudocode should include a loop to iterate through the list and a comparison to find the maximum value.
Activity 5: Binary Search ; O(log n)
Activity 6: Example: Sorting customer data for quick access; Quick Sort is chosen for its average-case efficiency.
Activity 7: O(n²) because it has nested loops iterating over n.
Activity 8: Inefficient algorithms increase processing time and resource usage, leading to slower software performance.
📚 Great books for Computing
Handpicked books to support learning at home · Amazon affiliate links
CGP KS2 Study Skills Book
How to learn effectively - revision tips and techniques
Usually ships in 24hrs
Scholastic Study Diary & Homework Planner
Helps children stay organised with homework and revision
Usually ships in 24hrs
Handwriting Practice Pad - Ages 5–7
Letter formation and joined-up writing practice
Usually ships in 24hrs
Staedtler Colouring Pencils 24 Pack
Quality pencils great for completing and illustrating worksheets
Usually ships in 24hrs