Faster index for property matching

In this paper, we revisit the Property Matching problem studied by Amir et al. [Property Matching and Weighted Matching, CPM 2006] and present a better indexing scheme for the problem. In particular, the data structure by Amir et al., namely PST, requires O(n log |Σ|+ n log log n) construction time and O(m log |Σ|+ K) query time, where n and m are the length of, respectively, the text and the pattern, Σ is the alphabet and K is the output size. On the other hand, the construction time of our data structure, namely IDS PIP, is dominated by suffix tree construction time and hence is O(n) time for alphabets that are natural numbers from 1 to a polynomial in n and O(n log σ) time otherwise, where σ = min(n, |Σ|). The query time is same as that of PST. Also, IDS PIP has the advantage that it can be built on either a suffix tree or a suffix array and additionally, it retains the capability of answering normal pattern matching queries.