Abstract

Suffix trees and suffix arrays are the most prominent full-text indices, and their construction algorithms are well studied. It has been open for a long time whether these indicescan be constructed in both o(n log n) time and o(n log n)-bit working space, where n denotes the length of the text. Inthe literature, the fastest algorithm runs in O(n) time, whileit requires O(n log n)-bit working space. On the other hand,the most space-efficient algorithm requires O(n)-bit work-ing space while it runs in O(n log n) time. This paper breaks the long-standing time-and-space bar-rier under the unit-cost word RAM. We give an algorithm for constructing the suffix array which takes O(n) time and O(n)-bit working space, for texts with constant-size alpha-bets. Note that both the time and the space bounds are optimal. For constructing the suffix tree, our algorithm re-quires O(n logffl n) time and O(n)-bit working space forany 0! ffl! 1. Apart from that, our algorithm can alsobe adopted to build other existing full-text indices, such as

Citations