DSA

Data Structures & Algorithms

Pattern-based problems with Java, Python, and C++ solutions. Curated lists, progress tracking, and company tags. Built for Amazon, Google, Meta, and top startups.

360+Problems
16Patterns
4Languages
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Practice by Pattern

The fastest way in: pick a pattern and start solving. Counts are live, and once you sign in each card shows how many you've cleared.

Learn the Patterns 16 topics with diagrams, template code in 4 languages, and practice problems
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Where to Start?

Solve in the browser

Problemset — code & run against tests in Python, Java, C++, JS. Every problem ships with a full editorial. Instant verdicts, saved to your profile.

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Learn the patterns first

DSA Fundamentals — 16 patterns with diagrams, template code, and practice problems.

1-2 days

Curated Problem Lists

Each list has LeetCode links + a progress tracker (checkboxes save in your browser automatically).

50 problems

Quick-Fire 50

Most-frequently asked, one per pattern. Complete in 7-10 days.
75 problems

The 75 — Interview Sprint

Every pattern with enough depth to be interview-ready. Complete in 4-5 weeks.
150 problems

The 150 — Complete Prep

Deep coverage: advanced graphs, 2D DP, bit manipulation. Complete in 6-8 weeks.

How to Practice Effectively

1
Pattern-first, not problem-first Learn the pattern → solve 3-5 problems → move to the next.
2
Time yourself 25 min per problem. Stuck at 15 min → read the approach (not code), retry.
3
Explain out loud If you can't explain it in English, you'll freeze in the interview.
4
Spaced repetition Solve → wait 3 days → re-solve without looking.
5
Track progress Use the checkboxes on each list page. Target: 3 per day, 6-8 weeks.