6 min read A decision procedure for recognizing which algorithm pattern a problem wants, with the trigger phrase, data structure, and canonical problems to drill for each. Read article
8 min read How trading firms grade the in-memory order book design problem, from the data structures that keep cancels O(1) to the follow-ups on price-time priority and self-trade prevention. Read article
6 min read What the standard containers in Python, Java, and C++ actually cost per operation, and the ones that quietly turn an O(n) loop into O(n squared). Read article
7 min read The per-operation cost of every common data structure, the amortized-versus-worst-case traps, and how to state complexity out loud without getting corrected. Read article
5 min read The balanced-brackets question is a stack in disguise, and the same move carries straight into Min Stack and Decode String. Read article
7 min read A reference table mapping fifteen coding-interview patterns to the signal that triggers each one and the canonical problem to learn it on. Read article
What's missing, wrong, or worth adding? One line helps.
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