Efficient implementation of lazy suffix trees

We present an efficient implementation of a write‐only top‐down construction for suffix trees. Our implementation is based on a new, space‐efficient representation of suffix trees that requires only 12 bytes per input character in the worst case, and 8.5 bytes per input character on average for a collection of files of different type. We show how to efficiently implement the lazy evaluation of suffix trees such that a subtree is evaluated only when it is traversed for the first time. Our experiments show that for the problem of searching many exact patterns in a fixed input string, the lazy top‐down construction is often faster and more space efficient than other methods. Copyright © 2003 John Wiley & Sons, Ltd.