Arrays & Linked List

Question 1

What is the difference between an array and a linked list?

Answer 1

Arrays allow random access (O(1)) but have fixed sizes; linked lists allow dynamic memory allocation but require sequential access (O(n)). Doubly linked lists can allow for o(1) ops

Question 2

What is the time complexity of accessing an element in an array?

Answer 2

O(1) (constant time).

Question 3

What is the time complexity of accessing an element in a singly linked list?

Answer 3

O(n) (linear time).

Question 4

What are the advantages of a doubly linked list over a singly linked list?

Answer 4

Doubly linked lists allow backward traversal and easier deletion but use extra memory. Can allow for o(1) operations

Question 5

How do you create a dummy node?

Answer 5

Initialize with let dummy = new ListNode(); let current = dummy;.

Question 6

How do you make a deep copy of a linked list?

Answer 6

1. Interleave new nodes with original nodes.
2. Assign random pointers for copied nodes.
3. Separate original and copied lists to restore structure.