1 / 10

Trie/Suffix Trie/Suffix Tree

Trie/Suffix Trie/Suffix Tree. Trie.

varuna
Download Presentation

Trie/Suffix Trie/Suffix Tree

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Trie/Suffix Trie/Suffix Tree

  2. Trie • A trie (from retrieval), is a multi-way tree structure useful for storing strings over an alphabet. It has been used to store large dictionaries of English (say) words in spelling-checking programs and in natural-language "understanding" programs. Given the data: • an, ant, all, allot, alloy, aloe, are, ate, be

  3. Tire (Cont.) • The idea is that all strings sharing a common stem or prefix hang off a common node. When the strings are words over {a..z}, a node has at most 27 children - one for each letter plus a terminator. • The elements in a string can be recovered in a scan from the root to the leaf that ends a string. All strings in the trie can be recovered by a depth-first scan of the tree.

  4. Suffix Trie • The idea behind suffix trie is to assign to each symbol in a text an index corresponding to its position in the text (i.e., first symbol has index 1, last symbol has index n = # of symbols in the text).

  5. Suffix Trie (Cont.) • A suffix trie is an ordinary trie in which the input strings are all possible suffixes. • A suffix of a text [t1 ... tn] is a substring [ti ... tn] where i is an integer between 1 and n.

  6. Suffix Trie (Cont.) • To demonstrate the structure of the resulting tree we will build the suffix trie corresponding to the following text: TEXT: G O O G O L $POSITION: 1 2 3 4 5 6 7

  7. Suffix Trie (Cont.)

  8. Suffix Tree • The suffix tree is created by compacting every unary node in the suffix trie.

  9. Suffix Tree (Cont.)

More Related