Radixfák

Radixfák, also known as radix trees or prefix trees, are specialized tree data structures that store a dynamic set of strings. Unlike binary search trees, nodes in a radix tree do not store entire keys. Instead, the path from the root to a node represents a prefix of one or more strings. Each edge in the tree is labeled with a character or a sequence of characters.

The primary advantage of radix trees lies in their efficient space and time complexity for certain operations, particularly prefix matching and string searching. When multiple strings share a common prefix, they are represented by a single path from the root, thus saving space. Searching for a string or a set of strings with a common prefix can be done in time proportional to the length of the prefix or the string, rather than the total number of strings.

Radix trees are particularly useful in applications such as spell checkers, autocompletion systems, IP routing tables, and database indexing. Different variants of radix trees exist, including compressed radix trees (often referred to as Patricia trees) which further optimize space by collapsing nodes with only one child, and ternary search trees, which use a different node structure. The fundamental principle, however, remains the efficient encoding of string prefixes.