Algorithms for Longest Common Abelian Factors

In this paper we consider the problem of computing the longest common abelian factor (LCAF) between two given strings. We present a simple $O(σ~ n^2)$ time algorithm, where $n$ is the length of the strings and $σ$ is the alphabet size, and a sub-quadratic running time solution for the binary string case, both having linear space requirement. Furthermore, we present a modified algorithm applying some interesting tricks and experimentally show that the resulting algorithm runs faster.