BST vs Hash Map Trade-offs for Ordered Data in DSA Typescript - Build Both Approaches

BST vs Hash Map Trade-offs for Ordered Data

📖 Scenario: Imagine you are managing a small library system. You want to store book titles and their number of copies. You want to quickly find how many copies a book has, but also sometimes list books in alphabetical order.

🎯 Goal: You will create a simple data structure using a JavaScript object (hash map) and a sorted array (to simulate BST behavior) to understand the trade-offs between fast lookup and ordered data.

📋 What You'll Learn

Create a hash map object called bookCopies with given book titles and copies

Create a sorted array called sortedBooks containing the book titles in alphabetical order

Write a function getCopiesFromMap that takes a book title and returns copies from the hash map

Write a function listBooksInOrder that returns the sorted list of book titles

Print the number of copies for a specific book using getCopiesFromMap

Print the list of books in alphabetical order using listBooksInOrder

💡 Why This Matters

🌍 Real World

Libraries, inventory systems, and many apps need to store data for quick lookup and sometimes in order for reports or display.

💼 Career

Understanding these trade-offs helps software developers choose the right data structure for performance and functionality.

1

Create the hash map of books and copies

Create a variable called bookCopies as an object with these exact entries: 'The Hobbit': 5, '1984': 8, 'Brave New World': 3, 'Fahrenheit 451': 6

DSA Typescript

// Create the bookCopies object with the given books and copies
// Your code here

Hint

Use curly braces {} to create an object and add key-value pairs for each book and its copies.

2

Create a sorted array of book titles

Create a variable called sortedBooks as an array containing the book titles from bookCopies sorted alphabetically

DSA Typescript

const bookCopies = {
  'The Hobbit': 5,
  '1984': 8,
  'Brave New World': 3,
  'Fahrenheit 451': 6
};

// Create sortedBooks array with book titles sorted alphabetically
// Your code here

Hint

Use Object.keys(bookCopies) to get the titles, then .sort() to order them alphabetically.

3

Write functions for lookup and ordered listing

Write a function called getCopiesFromMap that takes a parameter title and returns the number of copies from bookCopies. Also write a function called listBooksInOrder that returns the sortedBooks array

DSA Typescript

const bookCopies = {
  'The Hobbit': 5,
  '1984': 8,
  'Brave New World': 3,
  'Fahrenheit 451': 6
};

const sortedBooks = Object.keys(bookCopies).sort();

// Write function getCopiesFromMap(title) to return copies from bookCopies
// Write function listBooksInOrder() to return sortedBooks
// Your code here

Hint

Use simple functions that access the object and return the sorted array.

4

Print copies and ordered book list

Print the number of copies for the book '1984' using getCopiesFromMap('1984'). Then print the list of books in alphabetical order using listBooksInOrder()

DSA Typescript

const bookCopies = {
  'The Hobbit': 5,
  '1984': 8,
  'Brave New World': 3,
  'Fahrenheit 451': 6
};

const sortedBooks = Object.keys(bookCopies).sort();

function getCopiesFromMap(title: string): number {
  return bookCopies[title];
}

function listBooksInOrder(): string[] {
  return sortedBooks;
}

// Print copies of '1984'
// Print list of books in order
// Your code here

Hint

Use console.log to print the results of the function calls.