LeetCode Roadmap

A 5-stage LeetCode roadmap tailored for systems and HFT interviews. ~85 curated problems with progressive difficulty, each tied to a concrete pattern and a "why this matters" pedagogy. The stages: Stage 1 — Foundations (Weeks 1-3): Arrays & hashing, two pointers, stacks, binary search, linked lists. Every problem solvable in under 15 minutes once the data structure is internalized. Stage 2 — Recursive Thinking (Weeks 4-6): Binary trees, backtracking, and graph BFS/DFS. Learn to decompose problems before writing code. Stage 3 — Dynamic Programming (Weeks 7-10): 1D DP, 2D DP, and DP on trees/intervals. Each problem solved three ways: recursive brute force, top-down memo, bottom-up table. Stage 4 — Advanced Techniques (Weeks 11-15): Monotonic stacks, segment trees, union-find, binary search on answer, tries, combinatorics. The power-ups that turn "impossible" into "solvable". Stage 5 — Interview Simulation (Weeks 16-20): Timed random hards. Pattern recognition under pressure. Rust-specific idiom practice for systems interviews. Selected problems have in-depth writeups with intuition, annotated Rust code, complexity reasoning, worked traces, and pattern takeaways — the notes I wish I'd had when grinding for the Cybereason interview.