Group Anagrams Using Hash Map in DSA Python - Build from Scratch

Group Anagrams Using Hash Map

📖 Scenario: You work in a bookstore. You have a list of book titles, but some titles are anagrams of each other (words made by rearranging letters). You want to group these anagrams together to organize your inventory better.

🎯 Goal: Build a program that groups a list of words into lists of anagrams using a hash map (dictionary).

📋 What You'll Learn

Create a list of words called words with the exact values: 'listen', 'silent', 'enlist', 'hello', 'olleh', 'world'

Create an empty dictionary called anagram_groups to store grouped anagrams

Use a for loop with variable word to iterate over words

Inside the loop, create a variable sorted_word that holds the sorted letters of word joined back as a string

Use sorted_word as a key in anagram_groups and append word to the list of anagrams for that key

Print the list of grouped anagrams from anagram_groups.values()

💡 Why This Matters

🌍 Real World

Grouping anagrams helps organize words or data that are similar but shuffled, useful in spell checkers, word games, and data cleaning.

💼 Career

Understanding hash maps and grouping data is important for software developers working with data processing, search engines, and text analysis.

1

Create the list of words

Create a list called words with these exact strings: 'listen', 'silent', 'enlist', 'hello', 'olleh', 'world'

DSA Python

# Create the list of words
# Your code here

Hint

Use square brackets [] to create a list and separate words with commas.

2

Create the dictionary to hold anagram groups

Create an empty dictionary called anagram_groups to store the grouped anagrams

DSA Python

words = ['listen', 'silent', 'enlist', 'hello', 'olleh', 'world']
# Create an empty dictionary called anagram_groups
# Your code here

Hint

Use curly braces {} to create an empty dictionary.

3

Group words by sorted letters

Use a for loop with variable word to iterate over words. Inside the loop, create a variable sorted_word that holds the sorted letters of word joined back as a string. Then, if sorted_word is not a key in anagram_groups, add it with an empty list. Append word to the list for sorted_word in anagram_groups.

DSA Python

words = ['listen', 'silent', 'enlist', 'hello', 'olleh', 'world']
anagram_groups = {}
# Group words by their sorted letters
# Your code here

Hint

Use sorted(word) to get letters sorted, then ''.join(...) to make a string. Use if key not in dict to check keys.

4

Print the grouped anagrams

Print the list of grouped anagrams by printing list(anagram_groups.values())

DSA Python

words = ['listen', 'silent', 'enlist', 'hello', 'olleh', 'world']
anagram_groups = {}
for word in words:
    sorted_word = ''.join(sorted(word))
    if sorted_word not in anagram_groups:
        anagram_groups[sorted_word] = []
    anagram_groups[sorted_word].append(word)
# Print the grouped anagrams
# Your code here

Hint

Use print(list(anagram_groups.values())) to show grouped anagrams as a list of lists.