🧭
Track 00 · The Cartographer's Camp
PLAYABLEComplexity Foundations
data-structure selectionoperation countinggrowth ratesnested workspace complexityconstraint reading
6/6 canonical challenges · 6 authored chapters
Curriculum coverage
See what is available and what is still being built. These counts describe content coverage, not your personal progress.
Tracks
21
Core patterns
117
Authored challenges
219/219
Complete tracks
21/21
🏜️
Track 01 · The Dune Sea
PLAYABLEArrays and Hashing
index accessfrequency mapssetsprefix and suffixin-place mutationtwo pointers
12/12 canonical challenges · 7 authored chapters
⚙️
Track 02 · The Clockwork Market
PLAYABLESorting and Selection
comparison sortingcounting sortquickselectcustom orderingpartitioning
8/8 canonical challenges · 6 authored chapters
🪟
Track 03 · The Glass Canyon
PLAYABLESliding Window
fixed windowvariable windowfrequency windowmonotonic window
9/9 canonical challenges · 4 authored chapters
⛓️
Track 04 · The Chain Causeway
PLAYABLELinked Lists
pointer rewiringfast and slowdummy headmergereversal
9/9 canonical challenges · 5 authored chapters
🏛️
Track 05 · The Stacked Ruins
PLAYABLEStacks, Queues, and Deques
LIFOFIFOmonotonic stackmonotonic dequeexpression parsing
11/11 canonical challenges · 5 authored chapters
⛰️
Track 06 · The Split Peaks
PLAYABLEBinary Search
exact searchboundary searchsearch on answerrotated arraysmatrix search
10/10 canonical challenges · 6 authored chapters
🌉
Track 07 · The Overlap Isles
PLAYABLEIntervals
mergesweep linemeeting roomsschedulingdifference events
8/8 canonical challenges · 5 authored chapters
🌲
Track 08 · The Whisper Woods
PLAYABLETrees and BST
DFS traversalsBFS levelsBST invariantspath stateconstructionlowest ancestor
15/15 canonical challenges · 6 authored chapters
🔥
Track 09 · The Summit Forge
PLAYABLEHeaps and Priority Queues
top KK-way mergetwo heapsstreaming medianscheduling
8/8 canonical challenges · 6 authored chapters
🔤
Track 10 · The Glyph Garden
PLAYABLETries and Prefix Search
prefix treewildcard searchword boardautocomplete
6/6 canonical challenges · 4 authored chapters
🌀
Track 11 · The Branching Labyrinth
PLAYABLERecursion and Backtracking
decision treesubsetspermutationscombinationsconstraint pruningboard search
13/13 canonical challenges · 6 authored chapters
🌆
Track 12 · The Neon Grid
PLAYABLEGraphs
DFSBFSgrid floodtopological sortcycle detectionbipartite
15/15 canonical challenges · 6 authored chapters
🕸️
Track 13 · The Connected Expanse
PLAYABLEUnion Find
componentspath compressionunion by rankredundant edgeoffline connectivity
6/6 canonical challenges · 5 authored chapters
🚇
Track 14 · The Transit Nexus
PLAYABLEAdvanced Graphs
Dijkstraminimum spanning treeBellman FordFloyd WarshallEulerian path
9/9 canonical challenges · 5 authored chapters
🦌
Track 15 · The One-Way Steppe
PLAYABLEGreedy
exchange argumentlocal choiceschedulingjump reachabilitypartitioning
9/9 canonical challenges · 6 authored chapters
⛏️
Track 16 · The Memory Mines
PLAYABLEOne-Dimensional DP
state transitiontake or skipunbounded choicesubsequencestate compression
13/13 canonical challenges · 5 authored chapters
🔮
Track 17 · The Echo Matrix
PLAYABLETwo-Dimensional DP
grid pathsstring alignmentinterval DPknapsackmemoized search
12/12 canonical challenges · 5 authored chapters
🔭
Track 18 · The Binary Observatory
PLAYABLEBits, Math, and Geometry
bit masksXORinteger arithmeticcoordinatesmatrix transformsnumber theory
13/13 canonical challenges · 6 authored chapters
🏗️
Track 19 · The Architect's Citadel
PLAYABLEData Structure Design
LRU cacherandomized settime mapstream designrate tracking
10/10 canonical challenges · 6 authored chapters
🌐
Track 20 · The Scale Foundry
PLAYABLESystem Design
HLD and LLDrequirements and estimationAPI designdata modelingcachingqueues and streamspartitioningconsistencyreliabilitysecurityobservabilityarchitecture tradeoffscase studies
17/17 canonical challenges · 5 authored chapters