Complexity & Analysis
The vocabulary for saying how expensive something is — and knowing when the notation is lying to you.
4 topics
Big-O and asymptotic analysis
A vocabulary for describing how work grows with input size, deliberately blind to constants — which is both its power and its trap.
core25 minTime, space, and the tradeoff
Most optimisation is buying time with memory, and the interview signal is naming the price rather than paying it silently.
core20 minAmortised and average-case analysis
Why a dynamic array push is "O(1)" despite occasionally copying everything, and when that averaged promise is not the one you need.
deep20 minWhen complexity lies
Constants, cache locality, and small n routinely make the asymptotically worse algorithm the faster one on real hardware.
core25 min