Algorithms: String Matching

Algorithms that deal with strings and patterns, for example, searching for a pattern in a text string, are called string matching algorithms. Three popular string-matching algorithms are: 1. Naive approach 2. Boyer-Moore algorithm 3. KMP matching algorithm.

5 flashcards · Computer Science · by lakesare

  1. What's: shift invalid shift valid shift?

    Shift: The position before the complete/partial pattern occurs in text. Invalid Shift: The position after which partial matching occurs. Valid Shift: The position after which complete matching occurs.

  3. Write a naive string matching algorithm. includes(String string, String pattern)

    1. try 'i'2. 'i' == 'l'?3. if no - halt, try ' ' symbol. 1. try 'l'2. 'l' == 'l'?3. 'o' == 'o'?4. 'v' == 'v'?5. 'e' == 'e'?6. return true!

  4. How does Boyer-Moore Algorithm improve naive string-matching algorithm? Various implementations exist in different programming languages. In C++ it is part of the Standard Library since C++17, also Boost provides the generic Boyer–Moore search implementation under the Algorithm library. In Go (programming language) there is an implementation in search.go.D (programming language) uses a BoyerMooreFinder for predicate based matching within ranges as a part of the Phobos Runtime Library.The Boyer–…

  5. What's a trie? (pronounced 'try') Its name comes from a four-character substring of word ‘retrieval’.

    A trie is a tree-like data structure whose nodes store the letters of an alphabet. By structuring the nodes in a particular way, words and strings can be retrieved from the structure by traversing down a branch path of the tree. The main application is in information retrieval. The primary query operations that tries support are pattern matching and prefix matching.