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DSALet's find your starting point

A short quiz, no timer, no score. We plan your path from it.

Check my level

Up to 18 questions, about 10 minutes.

Start from the beginningI'll pick a level myself

The journey48 chapters

Three stops, from first steps to interview-ready. Nothing is locked, so open any chapter whenever you like.

  1. Beginnernot startedI can solve easy problems reliably.12 chaptersStarts with Complexity analysis
    1. not read yetB1Complexity analysis30 min7 exercises
    2. not read yetB2JavaScript toolkit42 min16 exercises
    3. not read yetB3Arrays & strings31 min32 exercises
    4. not read yetB4Prefix sums34 min21 exercises
    5. not read yetB5Hashing20 min20 exercises
    6. not read yetB6Two pointers29 min25 exercises
    7. not read yetB7Sliding window22 min19 exercises
    8. not read yetB8Binary search27 min24 exercises
    9. not read yetB9Basic recursion30 min13 exercises
    10. not read yetB10Sorting algorithms36 min15 exercises
    11. not read yetB11Stacks & queues21 min16 exercises
    12. not read yetB12Linked lists41 min29 exercises
  2. Intermediatenot startedI can solve mediums and recognize the pattern fast.22 chaptersStarts with Trees
    1. not read yetI1Trees23 min13 exercises
    2. not read yetI2BST operations44 min14 exercises
    3. not read yetI3Tree problems in depth28 min21 exercises
    4. not read yetI4Heaps & priority queues38 min24 exercises
    5. not read yetI5Graphs: representation22 min13 exercises
    6. not read yetI6BFS on grids42 min20 exercises
    7. not read yetI7Graph problems20 min15 exercises
    8. not read yetI8Topological patterns29 min11 exercises
    9. not read yetI9Backtracking22 min13 exercises
    10. not read yetI10DP: 1D29 min17 exercises
    11. not read yetI11DP: 2D41 min18 exercises
    12. not read yetI12DP state machines41 min18 exercises
    13. not read yetI13Greedy algorithms33 min16 exercises
    14. not read yetI14Intervals23 min12 exercises
    15. not read yetI15Bit manipulation27 min29 exercises
    16. not read yetI16Matrix problems17 min18 exercises
    17. not read yetI17Tries20 min9 exercises
    18. not read yetI18Monotonic stack & queue26 min15 exercises
    19. not read yetI19Math for interviews47 min19 exercises
    20. not read yetI20Design & simulation45 min16 exercises
    21. not read yetI21Divide and conquer52 min15 exercises
    22. not read yetI22Randomization58 min17 exercises
  3. Advancednot startedI can solve hards and design the efficient answer.14 chaptersStarts with Advanced DP
    1. not read yetA1Advanced DP42 min15 exercises
    2. not read yetA2Union-Find29 min14 exercises
    3. not read yetA3Advanced graph algorithms34 min14 exercises
    4. not read yetA4Minimum Spanning Tree28 min9 exercises
    5. not read yetA5Advanced graphs40 min13 exercises
    6. not read yetA6Segment & Fenwick trees33 min13 exercises
    7. not read yetA7Sparse tables38 min12 exercises
    8. not read yetA8String algorithms33 min13 exercises
    9. not read yetA9Design problems36 min13 exercises
    10. not read yetA10Advanced backtracking45 min12 exercises
    11. not read yetA11Games & probability DP73 min15 exercises
    12. not read yetA12Ordered structures63 min17 exercises
    13. not read yetA13Sweep line & geometry56 min17 exercises
    14. not read yetA14Interview strategy45 min7 exercises
Plan & levelchoose a level
Pick your level

Beginner

“I can solve easy problems reliably.”

12 chapters · 6h 3m · 217 exercises

Start with complexity analysis and the JavaScript toolkit, then what every pattern is built from: arrays, prefix sums, hashing, two pointers, sliding window, binary search, recursion, sorting, stacks and linked lists.

This is you if

  • You know JavaScript's arrays, objects and functions comfortably
  • You can solve some LeetCode Easy problems, slowly, by trial and error
  • You want Big-O and the foundational patterns once, in order
Show me this path
I've got

→ pick a run for tonight

Honest notes3 notes
  1. This curriculum is deliberately pattern-first, not problem-first — every chapter is "the shape of problem this solves," because that's what actually transfers to a problem you've never seen in an interview.
  2. Trees and graphs each get a structure chapter and a problems chapter, with the topics that depend on them (BSTs, grid BFS, topological sort, tries, the monotonic stack) placed in intermediate right after, because that split is where most intermediate candidates plateau.
  3. Interview strategy is its own advanced chapter, not an afterthought — knowing the patterns and communicating your thinking clearly under pressure are different skills, and top offers depend on both.