Famous lyrics by »
In computer science, the Cocke–Younger–Kasami algorithm (alternatively called CYK, or CKY) is a parsing algorithm for context-free grammars published by Itiroo Sakai in 1961. The algorithm is named after some of its rediscoverers: John Cocke, Daniel Younger, Tadao Kasami, and Jacob T. Schwartz. It employs bottom-up parsing and dynamic programming. The standard version of CYK operates only on context-free grammars given in Chomsky normal form (CNF). However any context-free grammar may be algorithmically transformed into a CNF grammar expressing the same language (Sipser 1997). The importance of the CYK algorithm stems from its high efficiency in certain situations. Using big O notation, the worst case running time of CYK is O ( n 3 ⋅ | G | ) {\displaystyle {\mathcal {O}}\left(n^{3}\cdot \left|G\right|\right)} , where n {\displaystyle n} is the length of the parsed string and | G | {\displaystyle \left|G\right|} is the size of the CNF grammar G {\displaystyle G} (Hopcroft & Ullman 1979, p. 140). This makes it one of the most efficient parsing algorithms in terms of worst-case asymptotic complexity, although other algorithms exist with better average running time in many practical scenarios.
0 fans
Share your thoughts on CYK with the community:
Report Comment
We're doing our best to make sure our content is useful, accurate and safe.
If by any chance you spot an inappropriate comment while navigating through our website please use this form to let us know, and we'll take care of it shortly.
Attachment
You need to be logged in to favorite.
Log In