Fenwick

Fenwick is primarily a surname of English origin and a place name in some parts of the United Kingdom. It is derived from older toponymic elements commonly interpreted as fen, meaning marsh or fen, and wic or wick, meaning dwelling or village. As a surname, Fenwick spread to other English-speaking countries through migration and colonization, and it has been borne by various individuals and descendants of families associated with places named Fenwick.

The Fenwick tree, also called a binary indexed tree, is a data structure used in computer science to efficiently compute prefix sums and perform updates on an array. It supports update and query operations in O(log n) time and uses O(n) space. By combining prefix sums, it enables range sum queries with a small constant factor. The structure is particularly popular in problems involving dynamic cumulative frequencies, competitive programming, and real-time statistics.

Beyond the data structure, Fenwick appears in names of organizations, buildings, and other entities drawn from the surname or the placename. In general usage, the term Fenwick most often refers to the Fenwick tree within computing contexts, while the surname and placename origins reflect its historical and genealogical roots.