3.1 Fundamentals of AlgorithmsStudy Notes

Deep Dive: Binary Search Steps

Part of Linear Search · GCSE GCSE Computer Science revision

This study notes covers Deep Dive: Binary Search Steps within Linear Search for GCSE Computer Science. Revise Linear Search in 3.1 Fundamentals of Algorithms for GCSE Computer Science with 15 exam-style questions and 8 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 5 of 8 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 5 of 8

Practice

15 questions

Recall

8 flashcards

Deep Dive: Binary Search Steps

To find 23 in [3, 7, 12, 23, 34, 45, 67]:

Find middle: 23 (index 3)
Compare: 23 == 23 ✓
Found! Return index 3

To find 45:

Middle: 23. Is 45 > 23? Yes. Look right half: [34, 45, 67]
Middle: 45. Is 45 == 45? Yes!
Found in 2 comparisons

Key formula: Maximum comparisons = log₂(n) + 1

Keep building this topic

Read this section alongside the surrounding pages in Linear Search. That gives you the full topic sequence instead of a single isolated revision point.

Comparison Memory Trick Video Lesson Finding the Needle

Practice Questions for Linear Search

How does a linear search work?

A. It divides the list in half repeatedly until the item is found
B. It checks each element in the list one at a time, from start to end
C. It sorts the list first, then jumps directly to the target item
D. It starts from the middle of the list and works outwards

1 markfoundation

Describe how a linear search works on a list of n items. [3 marks]

3 marksstandard

Quick Recall Flashcards

What does linear search do?

Checks each item from start to end until found

What does binary search require?

Data must be sorted

15 questions on Linear Search — practise free

Instant marking, adaptive difficulty, and 8 spaced repetition flashcards. Free until your GCSEs.

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Comparison

Memory Trick