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 ```python 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 ```mermaid 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