Top 20 Linked List Interview Questions with Answers

Linked List

Linked lists are a fundamental data structure commonly tested in coding interviews. Below are 20 essential linked list questions along with Python solutions.

1. What is a Linked List?

A linked list is a linear data structure where each element (node) contains a reference (or pointer) to the next node in the sequence.

2. Types of Linked Lists?

1. Singly Linked List: Nodes contain data and a pointer to the next node.
2. Doubly Linked List: Each node has two pointers, one to the next node and another to the previous node.
3. Circular Linked List: The last node returns to the first node, forming a loop.

3. Implement a Singly Linked List

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

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

    def append(self, data):
        new_node = Node(data)
        if not self.head:
            self.head = new_node
            return
        temp = self.head
        while temp.next:
            temp = temp.next
        temp.next = new_node

    def print_list(self):
        temp = self.head
        while temp:
            print(temp.data, end='…