Editing Radix tree (section)

== {{Anchor|PATRICIA}}History ==

The datastructure was invented in 1968 by Donald R. Morrison,<ref name="patricia">Morrison, Donald R. [http://portal.acm.org/citation.cfm?id=321481 PATRICIA -- Practical Algorithm to Retrieve Information Coded in Alphanumeric]</ref> with whom it is primarily associated, and by Gernot Gwehenberger.<ref>G. Gwehenberger,  [http://cr.yp.to/bib/1968/gwehenberger.html Anwendung einer binären Verweiskettenmethode beim Aufbau von Listen.] Elektronische Rechenanlagen 10 (1968), pp. 223–226</ref>

[[Donald Knuth]], pages 498-500 in Volume III of [[The Art of Computer Programming]], calls these "Patricia's trees", presumably after the acronym in the title of Morrison's paper: "PATRICIA - Practical Algorithm to Retrieve Information Coded in Alphanumeric".  Today, Patricia trees are seen as radix trees with radix equals 2, which means that each bit of the key is compared individually and each node is a two-way (i.e., left versus right) branch.