A fast order-preserving matching with q-neighborhood filtration using SIMD instructions

The order-preserving matching problem is a variant of the pattern matching problem focusing on shapes of sequences instead of values of sequences. Given a text and a pattern, the problem is to output all positions where the pattern and a subsequence in the text are of the same relative order. Chhabra and Tarhio proposed a fast algorithm based on filtration for the order-preserving matching problem, and Faro and Külekci improved Chhabra and Tarhio's solution by extending the filter. Furthermore, Cantone et al. and Chhabra et al. proposed solutions based on filtration using SIMD (Single Instruction Multiple Data) instructions, and showed that SIMD instructions are efficient in speeding up their algorithms. In this paper, we propose a fast matching algorithm for the order-preserving matching problem using SIMD instructions based on filtration proposed by Faro and Külekci. We show that our algorithm is practically faster than previous solutions.