Linked List vs Array When to Choose Which in DSA Python - Build Both Approaches

Linked List vs Array: When to Choose Which

📖 Scenario: Imagine you are organizing a line of people waiting for a concert ticket. Sometimes people join at the end, sometimes in the middle, and sometimes you need to quickly find someone by their position in line.Two ways to organize this line are using an array or a linked list. Each has its strengths and weaknesses depending on what you want to do.

🎯 Goal: You will create a simple array and a linked list with the same people. Then you will see how adding a person in the middle works differently for each. This will help you understand when to choose an array or a linked list.

📋 What You'll Learn

Create an array (list) with 5 people names

Create a linked list with the same 5 people names

Add a new person in the middle of the array

Add a new person in the middle of the linked list

Print both data structures after insertion to compare

💡 Why This Matters

🌍 Real World

Understanding when to use arrays or linked lists helps in organizing data efficiently in software like music playlists, text editors, or social media feeds.

💼 Career

Software developers and engineers often choose the right data structure to optimize performance and resource use in applications.

1

Create an array with 5 people names

Create a list called people_array with these exact names in order: 'Alice', 'Bob', 'Charlie', 'Diana', 'Ethan'

DSA Python

# Create the list people_array with the 5 names
# Your code here

Hint

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

2

Create a linked list with the same 5 people names

Define a class called Node with attributes name and next. Then create nodes for 'Alice', 'Bob', 'Charlie', 'Diana', and 'Ethan' linked in order, and assign the first node to a variable called people_linked_list

DSA Python

people_array = ['Alice', 'Bob', 'Charlie', 'Diana', 'Ethan']
# Define Node class and create linked list nodes
# Your code here

Hint

Each node stores a name and a link to the next node. Link nodes by setting node1.next = node2 and so on.

3

Add a new person in the middle of the array and linked list

Insert 'Frank' at index 2 in people_array. Then create a new Node with name 'Frank' and insert it after the node with name 'Bob' in people_linked_list

DSA Python

people_array = ['Alice', 'Bob', 'Charlie', 'Diana', 'Ethan']

class Node:
    def __init__(self, name):
        self.name = name
        self.next = None

node1 = Node('Alice')
node2 = Node('Bob')
node3 = Node('Charlie')
node4 = Node('Diana')
node5 = Node('Ethan')

node1.next = node2
node2.next = node3
node3.next = node4
node4.next = node5

people_linked_list = node1

# Insert 'Frank' at index 2 in people_array
# Insert 'Frank' node after 'Bob' in linked list
# Your code here

Hint

Use list.insert(index, value) for the array. For the linked list, create a new node and adjust the next links to insert it after 'Bob'.

4

Print both data structures after insertion

Print people_array. Then print the linked list names in order separated by -> and ending with null. Use variables current to traverse the linked list starting from people_linked_list.

DSA Python

people_array = ['Alice', 'Bob', 'Charlie', 'Diana', 'Ethan']

class Node:
    def __init__(self, name):
        self.name = name
        self.next = None

node1 = Node('Alice')
node2 = Node('Bob')
node3 = Node('Charlie')
node4 = Node('Diana')
node5 = Node('Ethan')

node1.next = node2
node2.next = node3
node3.next = node4
node4.next = node5

people_linked_list = node1

people_array.insert(2, 'Frank')

new_node = Node('Frank')
new_node.next = node2.next
node2.next = new_node

# Print people_array
# Print linked list names separated by '->' ending with 'null'
# Your code here

Hint

Use a while loop to go through the linked list nodes and build a string to print.