DSA TrackPattern-first curriculum
Learn patterns, not problems.
48 concepts from Big O to Dynamic Programming. Interactive step-through visualisations, pattern recognition quizzes, and guidedΒ βΒ expert practice modes.
⬑ 48 conceptsβ 14 patternsβ 120+ problemsπ SRS never-forget
6
Foundation
Free
5
Core
Pro
6
Advanced
Pro
120+
Problems
14
Patterns
β
Foundation
FreeΒ· 6 conceptsΞ©
beginnerFree
Big O & Complexity
Why algorithm efficiency matters. Time vs space tradeoffs and how to read Big-O notation.
Not started Β· 6 sections
β€
beginnerFree
Arrays
The foundation of everything: contiguous memory, index access, and in-place manipulation.
π Complete prerequisites first
β
beginnerFree
Two-pointer
Paired pointers solving sorted-array pair problems in O(n) β the first pattern that feels like magic.
π Complete prerequisites first
β§
beginnerFree
Sliding window
A window that grows and shrinks over an array to find optimal subarrays in O(n).
π Complete prerequisites first
β©
beginnerFree
Recursion & call stack
How functions call themselves: base cases, the call stack, and why recursion maps naturally to trees.
π Complete prerequisites first
#
beginnerFree
Hash maps
O(1) average-case lookup that turns O(nΒ²) nested loops into O(n) single passes.
π Complete prerequisites first
⬑
Core
ProΒ· 5 conceptsβ
intermediatePro
Linked lists
Fast/slow pointer, reversal in-place, and cycle detection β the classics.
π Pro required to access
β
intermediatePro
Stacks & queues
Monotonic stacks for next-greater problems, queues for BFS β when order of processing matters.
π Pro required to access
β
intermediatePro
Binary search
Binary search on the answer β not just arrays. Recognise the search space.
π Pro required to access
⬑
intermediatePro
Trees β BFS & DFS
Level-order vs depth-first. The stack and queue hidden beneath each traversal.
π Pro required to access
β¬’
intermediatePro
Graphs β BFS & DFS
Connected components, shortest paths, and island problems β graphs are just trees with cycles.
π Pro required to access
β
Advanced
ProΒ· 6 conceptsβ¦
advancedPro
Dynamic programming
Recognise overlapping subproblems. Top-down memoisation β bottom-up tabulation.
π Pro required to access
β©
advancedPro
Heaps & priority queues
K-th largest, merge K sorted lists β heap gives O(log n) min/max in O(1).
π Pro required to access
β³
advancedPro
Tries
Prefix trees for autocomplete and word search problems β O(L) lookup.
π Pro required to access
β
advancedPro
Union-Find
Disjoint-set union for dynamic connectivity β near-O(1) per operation.
π Pro required to access
β
advancedPro
Dijkstra's algorithm
Shortest path in weighted graphs β BFS meets a min-heap.
π Pro required to access
β‘
advancedPro
Topological sort
Task scheduling and dependency resolution in directed acyclic graphs.
π Pro required to access
Ready to unlock everything?
Free
- β6 Foundation concepts
- βTypeScript only
- βStep-through visualisers
- βPattern recognition quizzes
- βNotes + SRS flashcards
Pro
TechCookies Pro
- βAll 17 concepts unlocked
- βJava Β· Python Β· Go + TypeScript
- βExpert mode β hints disabled
- β120+ practice problems
- βWeak-area detection