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Lessons, practice lists, guides, videos, company guides and the system design roadmap open for anyone. You need an account only to save.
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Free pages open without an account, USACO joins Practice, system design gets a roadmap with concept lessons, and every lesson was rewritten around interactive widgets.
Lessons, practice lists, guides, videos, company guides and the system design roadmap open for anyone. You need an account only to save.
515 USACO contest problems since the 2015-16 season, in four divisions with bosses, badges and links to USACO Guide solutions.
System design opens on a roadmap: a free Foundations trunk, five branches and eight interactive concept lessons, starting with Backpressure.
Lessons open on a concrete problem and teach with widgets you can change: push and pop a stack, flip bits, move two pointers.
New chapters on time complexity from constraints, modular arithmetic, complete search, sorting with comparators, and tree DP.
Sets with more than 24 problems open on their starred problems, with an All problems switch to show the rest.
AtCoder’s Boot camp Easy 100, CSES Range Queries, the AtCoder Library Practice Contest and AtCoder’s Let’s use segtree! contest.
Company prep covers 69 employers in 96 India and US guides, each card in the company’s own colour with its real logo.
Each branch of the Learn map hangs its chapters from one centre line. Stars mark key topics, and fog covers advanced chapters.
Fog was removed on 26 October 2026. Advanced chapters now stay readable on the map.
All 536 subscriber-only LeetCode problems, placed in the 27 LeetCode chapters, for Interview Prep and Oni pass holders.
Retired on 26 October 2026. Arise no longer lists LeetCode Premium problems; solves you saved earlier keep their XP.
The footer is a pixel-grain coast with a lighthouse, a torii and a distant volcano: dawn in the light theme, night in the dark theme.
Replaced on 27 October 2026 by a lake footer with a paper crane.
Chapters split into Lesson and Practice views, 1,219 problems got hint ladders, every set ends in a boss, and all judges share one practice layout.
Each chapter has a Lesson view and a Practice view. Wide screens add a side column with the lesson’s sections and your solved count.
The Learn map changes with your goal. Contest mode adds CSES and AtCoder sets beside chapters and a path to Codeforces from 1200.
One click on Hint opens the first step. Each ladder holds one to four hints, followed by the approach and the topic.
Each Codeforces band, LeetCode chapter and CSES or AtCoder collection ends with a boss problem, and mini bosses sit partway through.
LeetCode, Codeforces, CSES, AtCoder and the beginner tracks share one layout: a sidebar of sets, a set header and one problem list.
Spaced review shows what is due today and over the next 14 days. You grade each attempt from Nothing to Easy.
The All time board ranks members who opt in by the XP they earned, counting at most 15 solves a day. The top three stand on a podium.
Interview templates gained Rust versions, nine new templates come in Python, C++ and Rust, and six contest starter files are free.
The header has five sections, each chapter opens one workspace, lesson exercises run in C++ as well as Python, and study sprints help you plan your weeks.
A chapter’s explanation, exercise and judge problems sit in one place, with a searchable chapter list and the next chapter at the end.
Signed-in learners can write lesson exercises in C++, and C++ drafts save apart from Python ones.
Plan 4 or 8 weeks of practice around your goal and the time you have each day. Anyone can open the seven-day sample week.
Interactive lessons, practice across four judges, timed grade assessments, video lessons and accounts that save your progress.
Each chapter on the Learn map teaches one idea with a worked example, a trace you can step through, hints and a Python exercise.
Click a problem title to read its statement, math, examples and constraints in a floating window, without leaving the list.
Each grade from E to SS has a timed test of two problems. Qualify through practice, then pass the test to earn the next grade.
Create an account to save progress across devices. Your player card shows your level, XP and medals, and downloads as an image.
One-minute explanations of Two Sum, Koko Eating Bananas and Valid Parentheses, each with hints and a synced transcript.
Company prep separates the interview format a company publishes from what candidates report, and dates every report.