Constant-space string matching in sublinear average time

International audienceGiven two strings: pattern P of length m and text T of length n. The string-matching problem is to find all occurrences of the pattern P in the text T. We present a simple string-matching algorithm which works in average o(n) time with constant additional space for one-dimensional texts and two-dimensional arrays. This is the first attempt to the small-space string-matching problem in which sublinear time algorithms are delivered. More precisely we show that all occurrences of one- or two-dimensional patterns can be found in O(n/r) average time with constant memory, where r is the repetition size (size of the longest repeated subword) of