Free DSA for beginners

Learn. Code.
Crack.

A calm, step-by-step way to learn data structures and algorithms. One small idea at a time, with hints whenever you get stuck.

Start your first lesson Browse the roadmap →
53patterns, in order
312practice problems
0setup needed
01

Learn

53 patterns in order, starting from loops. Each guide explains the why before the code.

Open the roadmap → 02

Code

Solve 312 problems right in your browser in Java, Python or JavaScript. Nothing to install.

Start practising → 03

Crack

Pattern quizzes and timed mock interviews tell you when you're ready.

Take a mock test →
Try a hint

Stuck? Take one small hint.

Every problem has a three-step hint ladder. Each hint nudges you a little further, without giving away the answer.

EasyHashMap

Two Sum

Everything's free

All in your browser.
No setup.

Your progress is saved on this device as you go.

01

Practice console

Write code, run sample tests, then submit against hidden tests. Hints and solutions when you need them.

→ 02

Pattern quiz

Read a problem with the title hidden and guess the pattern. The skill interviews really test.

→ 03

Mock interviews

Timed rounds in four formats, with a score at the end.

→ 04

Smart revision

Solved problems come back after 3, 7, 21 and 60 days, so they stick.

→ 05

Study planner

Enter your interview date and get a day-by-day plan.

→
Coming soon

Hints right inside LeetCode.

The AlgoSolveo browser extension is on its way. Get one email on launch day.

FAQ

Questions, answered.

Yes. The roadmap, all 312 problems, hints, solutions, quizzes and mock tests are free.
Start at Stage 1, Foundations. It begins with loops and basic maths, then arrays, hashing, sorting and 2D arrays, before any interview patterns.
Java, Python and JavaScript, all running in your browser. Nothing to install.
No. Practice saves your progress on this device. Sign in with Google to see your dashboard.
They follow the same patterns, but every problem, test and solution here is written by AlgoSolveo.

Your first pattern
takes ten minutes.

Start with loops. We'll take it from there.

Start your first lesson