Improved multi-keyword matching algorithm

An improved algorithm for matching multiple strings is suggested. The new algorithm, named QMS (quick multi-pattern search), is based on the analysis of Sun Wu algorithm and the idea of QS (quick search) algorithm. QMS uses HASH table and PREFIX table to decrease the number of comparisons. During the computation of the shift distance, the character closely after the current window is considered. Thus shift distances are computed with more accurate technique, and larger average shift distance is acquired. The scanning efficiency and the space utility are improved in result. Series of tests on an actual corpus show that QMS algorithm is much more efficient than Sun Wu algorithm under usual circumstances.