Interview prep

Core CS

Interviews are not only DSA. Write short answers; the tutor grades them and strengthens your outline.

OOPs (C++)

Difference between encapsulation and abstraction with a C++ example idea.

Why do we need virtual functions? What is a vtable at a high level?

When should you write your own copy constructor in C++?

Single vs multiple inheritance in C++. Diamond problem — how does virtual inheritance help?

Compile-time vs runtime polymorphism examples in C++.

Explain 1NF, 2NF, 3NF in one sentence each with why we care in interviews.

When does an index help SELECT but hurt INSERT/UPDATE? Tradeoff?

Expand ACID and give a real-world analogy for Atomicity.

INNER vs LEFT JOIN — when do you get NULLs?

Name dirty read / non-repeatable read / phantom. Which isolation stops dirty reads?

Process vs Thread — memory, creation cost, when to use which.

Four Coffman conditions for deadlock. Name one prevention strategy.

Compare FCFS, SJF, Round Robin in one line each.

What is paging? What is a page fault at a high level?

Mutex vs binary semaphore — key differences for interviews.

TCP vs UDP — reliability, ordering, use-cases.

What does HTTPS add on top of HTTP? Where do certificates fit?

Name OSI layers and one protocol/example at Transport and Application.

What does DNS do? Walk a browser request from URL to IP at a high level.

Explain TCP 3-way handshake in 3 bullets.