Compact Directed Acyclic Word Graphs for a Sliding Window

The suffix tree is a well-known and widely-studied data structure that is highly useful for string matching. The suffix tree of a string w can be constructed in O(n) time and space, where n denotes the length of w. Larsson achieved an efficient algorithm to maintain a suffix tree for a sliding window. It contributes to prediction by partial matching (PPM) style statistical data compression scheme. The compact directed acyclic word graph (CDAWG) is a more space-economical data structure for indexing a string. In this paper we propose a linear-time algorithm to maintain a CDAWG for a sliding window.