Efficient Lyndon Factorization of Grammar Compressed Text

We present an algorithm for computing the Lyndon factorization of a string that is given in grammar compressed form, namely, a Straight Line Program (SLP). The algorithm runs in O(n + mnh) time and O(n) space, where m is the size of the Lyndon factorization, n is the size of the SLP, and h is the height of the derivation tree of the SLP. Since the length of the decompressed string can be exponentially large w.r.t. n,m and h, our result is the first polynomial time solution when the string is given as SLP.