Always reach for the asymptotically-optimal data structure — challenged

Everyone reaches for the hash map. O(1) lookup — can't beat that, right? Wrong. For most production lookups, a flat array with a linear scan is faster. I've seen this matter in real systems. Not because Big-O is a lie. Because Big-O describes the shape of the curve, not the constant factor. A hash map pays a hashing cost on every call. Its bucket... Weiterlesen