a suffix tree T for a string S of length m is tree with the following properties: –! A trie is a tree-like information retrieval data structure whose nodes store the letters of an alphabet. It is also known as a digital tree or a radix tree or prefix tree. In a trie, on each edge you write a single letter, while in a PATRICIA tree (or radix tree) you store whole words. The construction of such a tree for the string takes time and space linear in the length of .Once constructed, several operations can be performed quickly, for instance locating a substring in , locating a substring if a certain number of mistakes are allowed, locating matches for a regular expression pattern etc. Tries were introduced in the 1960's by Fredkin. concatenation of edge labels on path A radix tree is a compressed version of a trie. A suffix tree is a member of the trie … A suffix tree is built on top of a trie, so it is necessary to have some rudimentary understanding of the trie. Suffix Tree Definition •! 后缀树（Suffix Tree）是一棵 Compressed Trie，其存储的关键词为 Text 所有的后缀。后缀树的性质：存储所有 n(n-1)/2 个后缀需要 O(n) 的空间，n 为的文本（T m leaves, labeled 1 to m –! At any time, Ukkonen’s algorithm builds the suffix tree for the characters seen so far and so it has on-line property that may be useful in some situations. In an overly simplified manner, the prefix and suffix distinction can serve as a mnemonic device to differentiate between a trie and a suffix tree, which is to remember that the latter deals with suffixes while the former, prefixes. Now, assume you have the words hello, hat and have.To store them in a trie, it would look like: The true suffix tree for S is built from T m by adding $. Implicit suffix tree T i +1 is built on top of implicit suffix tree T i. rooted and directed –! Here is some general information on tries: The term trie comes from the word "retrieval". Let us understand Compressed Trie with the following array of words. We have discussed Standard Trie. each edge labeled by a substring of S –! This lecture is about tries and suffix trees. A Suffix Tree for a given text is a compressed trie for all suffixes of the given text.