Hash map vs hash set in Data Structures Theory - Hands-On Comparison

Understanding Hash Map vs Hash Set

📖 Scenario: You are organizing a collection of items for a small library. You want to keep track of books and also maintain a list of unique genres available.

🎯 Goal: Build a simple data structure example to understand the difference between a hash map and a hash set by storing book titles with authors and a set of unique genres.

📋 What You'll Learn

Create a dictionary to store book titles as keys and authors as values.

Create a set to store unique genres.

Add at least three books with their authors to the dictionary.

Add at least three genres to the set, including duplicates to show uniqueness.

Demonstrate the difference between storing key-value pairs and unique items.

💡 Why This Matters

🌍 Real World

Libraries, inventory systems, and many applications use hash maps to store paired data like names and details, and hash sets to keep track of unique categories or tags.

💼 Career

Understanding hash maps and hash sets is fundamental for software developers, data analysts, and anyone working with data structures to efficiently store and retrieve information.

1

Create a dictionary for books

Create a dictionary called books with these exact entries: '1984': 'George Orwell', 'To Kill a Mockingbird': 'Harper Lee', and 'The Great Gatsby': 'F. Scott Fitzgerald'.

Data Structures Theory

# Create the books dictionary with titles and authors
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys as book titles and values as authors.

2

Create a set for genres

Create a set called genres with these exact values: 'Fiction', 'Classic', and 'Fiction' (include the duplicate to show uniqueness).

Data Structures Theory

books = {
    '1984': 'George Orwell',
    'To Kill a Mockingbird': 'Harper Lee',
    'The Great Gatsby': 'F. Scott Fitzgerald'
}
# Create the genres set with duplicates
# Your code here

Need a hint?

Use curly braces {} to create a set. Sets automatically remove duplicates.

3

Add a new book and genre

Add a new entry to the books dictionary with key 'Brave New World' and value 'Aldous Huxley'. Then add the genre 'Dystopian' to the genres set.

Data Structures Theory

books = {
    '1984': 'George Orwell',
    'To Kill a Mockingbird': 'Harper Lee',
    'The Great Gatsby': 'F. Scott Fitzgerald'
}
genres = {'Fiction', 'Classic', 'Fiction'}
# Add a new book and a new genre
# Your code here

Need a hint?

Use square brackets [] to add a key-value pair to the dictionary. Use the add() method to add an item to the set.

4

Explain the difference

Add a comment explaining that books is a hash map storing key-value pairs, while genres is a hash set storing unique items without duplicates.

Data Structures Theory

books = {
    '1984': 'George Orwell',
    'To Kill a Mockingbird': 'Harper Lee',
    'The Great Gatsby': 'F. Scott Fitzgerald'
}
genres = {'Fiction', 'Classic', 'Fiction'}
books['Brave New World'] = 'Aldous Huxley'
genres.add('Dystopian')
# Add a comment explaining the difference between books and genres
# Your code here

Need a hint?

Write a clear comment starting with # describing the difference between the dictionary and the set.