Collision handling (chaining) in Data Structures Theory - Mini Project: Build & Apply

Collision handling (chaining)

📖 Scenario: Imagine you are designing a simple phone book that stores names and phone numbers. Sometimes, two people might have names that lead to the same storage spot. To handle this, you use a method called chaining, where each spot holds a list of entries.

🎯 Goal: You will build a basic structure to show how collision handling with chaining works by creating a hash table with lists to store multiple entries in the same spot.

📋 What You'll Learn

Create a hash table with fixed size and empty lists for each slot

Define a simple hash function to find the slot for a name

Add entries to the hash table using chaining to handle collisions

Show the final hash table structure with all entries stored

💡 Why This Matters

🌍 Real World

Hash tables with chaining are used in many software systems to store and quickly find data even when keys collide.

💼 Career

Understanding collision handling is important for software developers working with databases, caching systems, and performance-critical applications.

1

Create the hash table structure

Create a variable called hash_table that is a list with 5 empty lists inside it.

Data Structures Theory

hash_table = [[] for _ in range(5)]  # Create a list with 5 empty lists

Need a hint?

Use a list comprehension to create 5 empty lists inside hash_table.

2

Define the hash function

Create a function called hash_function that takes a parameter key and returns the length of key modulo 5.

Data Structures Theory

def hash_function(key):
    # Your code here
    pass

Need a hint?

The hash function uses the length of the key and divides by 5, returning the remainder.

3

Add entries using chaining

Use the hash_function to find the index for each name in the list entries = [("Anna", "123"), ("Bob", "456"), ("Clara", "789"), ("Dave", "012"), ("Eve", "345")]. Then add each tuple to the correct list inside hash_table.

Data Structures Theory

entries = [("Anna", "123"), ("Bob", "456"), ("Clara", "789"), ("Dave", "012"), ("Eve", "345")]

for name, number in entries:
    # Your code here
    pass

Need a hint?

Loop over each entry, find the index using the hash function, then add the entry to the list at that index.

4

Complete the hash table setup

Add a final line that assigns the variable final_table to the current hash_table to represent the completed structure.

Data Structures Theory

final_table = hash_table  # Assign the completed hash table
# Your code here

Need a hint?

This final step just saves the current hash table into final_table to show the completed chaining structure.