Boyer
v1.5Fast string search (indexOf) using the Boyer-Moore algorithm. Incorporate this class into your own Java programs to rapidly search strings. Boyerr-Moore is about twice as fast as String.indexOf when t...
Description
Fast string search (indexOf) using the Boyer-Moore algorithm. Incorporate this class into your own Java programs to rapidly search strings.
use: import com.mindprod.Boyer.Boyer; ... Boyer b = new Boyer("dogcatwombat"); int where = b.indexOf("cat"); or int where = Boyer.indexOf("dogcatwombat","cat"); Boyer-Moore is about twice as fast as String.indexOf when the string you are searching in is 2K or over and the pattern you are searching for is 4 characters or longer.
String.indexOf is particularly slow when the pattern begins with a common letter such as "e". Boyer-Moore is fastest when the pattern is long and composed only of uncommon letters, e.g.
"z" or "^". If you use a char[] instead of String for your text to be searched, it will run an additional 33% faster.
Boyer automatically reverts to String.indexOf when that would be faster.
use: import com.mindprod.Boyer.Boyer; ... Boyer b = new Boyer("dogcatwombat"); int where = b.indexOf("cat"); or int where = Boyer.indexOf("dogcatwombat","cat"); Boyer-Moore is about twice as fast as String.indexOf when the string you are searching in is 2K or over and the pattern you are searching for is 4 characters or longer.
String.indexOf is particularly slow when the pattern begins with a common letter such as "e". Boyer-Moore is fastest when the pattern is long and composed only of uncommon letters, e.g.
"z" or "^". If you use a char[] instead of String for your text to be searched, it will run an additional 33% faster.
Boyer automatically reverts to String.indexOf when that would be faster.
