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Every track has a course behind it: video lectures, animated walkthroughs, a written reference, and a checkpoint quiz that has to pass before the track counts as done.
Binary trees, BSTs, and the recursive shape behind most tree problems.
Fixed and variable windows, and the invariant that tells you when to shrink.
Base cases, call stacks, and pruning search trees before they explode.
Frequency maps, seen-sets, grouping keys, and when O(1) stops being O(1).
Reading a bound off code, amortised analysis, and space you forgot to count.
Representation, BFS and DFS, cycles, topological order, components.
Memoisation to tabulation, state design, and the eight core recurrences.
The twelve shapes that cover most technical screens, with live mock rounds.