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Computer Science

GCSE · AQA

QuestionsFlashcards

Representing Algorithms
Efficiency of Algorithms
Searching Algorithms
Sorting Algorithms

Data Types
Programming Concepts
Arithmetic, Relational & Boolean Operations
Data Structures
Input, Output & String Handling
Random Number Generation
Subroutines & Structured Programming
Robust & Secure Programming

Number Bases & Conversions
Units of Information
Binary Arithmetic
- Binary Addition
  3
- Binary Shifts
  6
Character Encoding
Representing Images
Representing Sound
Data Compression

Hardware & Software
Boolean Logic
Programming Languages & Translators
CPU & the Fetch-Execute Cycle
Memory & Storage
Embedded Systems

Network Types & Connections
Protocols & the TCP/IP Model
Network Security

Cyber Security Threats
Social Engineering
- What Social Engineering Is
  4
- Blagging, Phishing & Shouldering
  5
Malware
- What Malware Is
  2
- Viruses, Trojans & Spyware
  3
Detecting & Preventing Threats

Relational Databases
SQL

Ethical, Legal & Environmental Impacts

Sherpa Study
GCSE Computer Science
AQA Flashcards
3. Fundamentals of Data Representation
Data Compression
Huffman & ASCII Bit Calculations

Huffman & ASCII Bit Calculations Flashcards

All 3 cards in this deck

How do you work out the number of bits needed to store uncompressed text in ASCII?: Number of characters $\times$ 7, because ASCII uses 7 bits per character.
How do you work out the number of bits needed to store text compressed with Huffman coding?: For each character, multiply its frequency by the length of its code, then add these together.
How do you work out the number of bits saved by Huffman coding?: Bits saved = bits needed in 7-bit ASCII − bits needed using the Huffman codes.