Mastering Data Structures

Front

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

Back

The main difference is that arrays have fixed sizes and allow index-based access, while linked lists are dynamic and consist of nodes linked by pointers.

Front

How do you insert an element at the beginning of a linked list?

Back

Create a new node, set its next to the current head, and update the head to the new node.

Front

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

Back

O(1)

Front

Explain the concept of a stack and its main operations.

Back

A stack is a LIFO data structure with main operations: push (add), pop (remove), and peek (view top).

Front

What is the difference between a stack and a queue?

Back

A stack uses LIFO, while a queue uses FIFO.

Front

How do you implement a queue using two stacks?

Back

Use two stacks: one for enqueueing and one for dequeueing. Transfer elements from the first stack to the second when needed.

Front

What is a binary tree and how does it differ from a binary search tree?

Back

A binary tree is a tree structure with nodes having at most two children; a binary search tree is a binary tree with ordered nodes.

Front

What traversal methods can be used on trees?

Back

Depth-First Search (DFS) and Breadth-First Search (BFS) including Pre-order, In-order, Post-order for DFS.

Front

Define a graph and its components.

Back

A graph is defined by its components: vertices (nodes) and edges (connections between nodes).

Front

What is the difference between directed and undirected graphs?

Back

Directed graphs have directed edges; undirected graphs have undirected edges.