Abstract
A new string-matching algorithm working in constant space and linear time is presented. It is based on a powerful idea of sampling, originally introduced in parallel computations. The algorithm uses a sample S which consists of two positions inside the pattern P. First the positions of the sample S are tested against the corresponding positions of the text T, then a version of Knuth-Morris-Pratt algorithm is applied. This gives the simplest known string-matching algorithm which works in constant space and linear time and which does not use any linear order of the alphabet. A refined version of the algorithm gives the fastest (in the sense of number of comparisons) known algorithm for string-matching in constant space. It makes (1+ε)n+O(n/m) symbol comparisons. This improves substantially the result of [3], where a (3/2+ε)n comparisons constant space algorithm was designed. Additionally, our preprocessing to this algorithm makes only (1+ε)m+O(1/ε) comparisons and uses constant space.
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© 1995 Springer-Verlag Berlin Heidelberg
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Gasieniec, L., Plandowski, W., Rytter, W. (1995). Constant-space string matching with smaller number of comparisons: sequential sampling. In: Galil, Z., Ukkonen, E. (eds) Combinatorial Pattern Matching. CPM 1995. Lecture Notes in Computer Science, vol 937. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-60044-2_36
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DOI: https://doi.org/10.1007/3-540-60044-2_36
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