Linked List Concept

Python uses dynamic arrays for lists, but linked lists are still important to understand.

What is a linked list?

A chain of nodes:

• each node holds a value
• each node points to the next node

Why learn it?

• helps you understand pointers and memory ideas
• useful in interviews and some system designs

Node and list implementation

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

class LinkedList:
    def __init__(self):
        self.head = None

    def add_front(self, value):
        self.head = Node(value, self.head)

    def to_list(self):
        out = []
        cur = self.head
        while cur:
            out.append(cur.value)
            cur = cur.next
        return out

ll = LinkedList()
ll.add_front(3)
ll.add_front(2)
ll.add_front(1)
print(ll.to_list())  # [1,2,3]

Graph: linked list

flowchart LR
  A[Node 1] --> B[Node 2]
  B --> C[Node 3]
  C --> D[None]

Remember

• Linked lists excel at insert/remove at head
• Random access (indexing) is slow
• Python list is usually better in real Python apps