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Data structures and algorithms, taught with working code. Arrays to graphs, in the order the ideas build.
3 courses · 305 lessons · work through them in order, top to bottom
Python · Beginner
Complexity, arrays, hash maps, trees, graphs and first DP.
Python-first interview foundations: Big-O counted in code, arrays, strings, hash maps, two pointers, stacks, linked lists, trees, graphs, and a first taste of dynamic programming.
100 lessons · 18 topics · 0/100 completed
Python · Intermediate
Patterns, heaps, tries, graphs and the DP ladder.
Pattern recognition for real interviews: monotonic stacks, heaps, backtracking, tries, union-find, Dijkstra, greedy and the dynamic programming ladder — plus an LRU cache and a mini search engine capstone.
112 lessons · 20 topics · 0/112 completed
Python · Advanced
Hard problems, proofs and from-scratch structures.
The hard canon: median of two sorted arrays, segment trees, interval DP, string algorithms, MST and shortest paths in depth, LFU and design problems — ending in a timed mock-interview gauntlet.
93 lessons · 17 topics · 0/93 completed