Update Query Time Trade-Off for Dynamic Suffix Arrays

The Suffix Array SA(S) of a string S[1 … n] is an array containing all the suffixes of S sorted by lexicographic order. The suffix array is one of the most well known indexing data structures, and it functions as a key tool in many string algorithms. In this paper, we present a data structure for maintaining the Suffix Array of a dynamic string. For every 1 ≤ k ≤ n, our data structure reports SA[i] in 𝒪̃(n/k) time and handles text modification in 𝒪̃(k) time. Additionally, our data structure enables the same query time for reporting iSA[i], with iSA being the Inverse Suffix Array of S[1 … n]. Our data structure can be used to construct sub-linear dynamic variants of static strings algorithms or data structures that are based on the Suffix Array and the Inverse Suffix Array.