Coding interview questions by topic

Most coding interview problems are a small number of patterns in different clothes. Learning to recognise the pattern from the wording is faster than memorising solutions, and it is what interviewers hope to see you do.

What are the most common coding interview topics?

The most common topics are arrays and hashing, two pointers, sliding window, stacks, binary search, linked lists, trees, graphs, heaps, dynamic programming, backtracking and tries. Each has a recognisable pattern; learn the signals that suggest it and a template for solving it.

Take a topic-based interview

How to use these pages

Each topic page lists the signals that suggest the pattern, a way to build the solution, named classic problems to practise and the mistakes interviewers see most. Read one, then take a practice interview on that topic, and say the pattern out loud before you code.

Practising by topic

Topic-based interviews on giveinterview give you several questions from the topics you choose, including problems you have not seen, which is closer to a full coding round than a single question. Your first 3 single-question interviews are free for life, every interview report is free, and a new account also gets 6 welcome credits.

In this section

Frequently asked questions

Which topic should I learn first?

Start with arrays and hashing, two pointers and sliding window. They are the most common in early rounds and they teach the habit of trading memory for time.

How many problems do I need to solve?

Quality beats count. Solving a problem, then explaining why the pattern fits and what you would change if a constraint moved, teaches more than rushing through many.