Radix Tree - Wikipedia
Fleeting- External reference: https://en.wikipedia.org/wiki/Radix_tree
a data structure that represents a space-optimized trie (prefix tree) in which each node that is the only child is merged with its parent
patricia trie
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.