DERIVING A FAST SYSTOLIC ALGORITHM FOR THE LONGEST COMMON SUBSEQUENCE PROBLEM

The longest common subsequence (LCS) problem is to find an LCS of two given sequences and the length of the LCS. In this paper, an efficient systolic algorithm for the LCS problem is derived. For two sequences of length m and n, where m ≥ n, the problem can be solved with only [n/2] processors in m + 2[n/2] − 1 time steps. Compared with other systolic algorithms that solve the LCS problem, our algorithm not only takes fewer time steps but also uses fewer processors. Our algorithm is better suited to implementation on multicomputers than other systolic algorithms.