 
Summary: A Modification of the LandauVishkin
Algorithm Computing Longest Common
Extensions via Suffix Arrays
Rodrigo de Castro Miranda1
and Mauricio AyalaRinc´on1
Mestrado em Inform´atica e Departamento de Matem´atica, Universidade de Bras´ilia,
Brasil
rodrigo.miranda@acm.org,ayala@mat.unb.br
Abstract. Approximate string matching is an essential problem in many
areas related to Computer Science including biological sequence process
ing. The standard solution of this problem is an O(mn) running time and
space dynamic programming algorithm for two strings of length m and
n. Landau and Vishkin developed an algorithm which uses suffix trees
for accelerating the computation along the dynamic programming table
and reaching space and running time in O(nk), where n > m and k is the
maximum number of admissible differences. Suffix trees are used for pre
processing the sequences allowing an O(1) running time computation of
the longest common extensions between substrings. One of the practical
drawbacks of the LandauVishkin algorithm is the excessive use of space
inherent to the use of suffix trees. In fact, although suffix trees can be
