Multi-mode string matching algorithm based on extended precision chaos hash

Abstract

The invention discloses a multi-mode string matching algorithm based on extended precision chaos hash. The main data structure in the algorithm comprises a character table containing control status information, a hash table with a mode mapped by an extended precision chaos hash function, and window information of multi-mode length information. The algorithm comprises the following steps: 1. preprocessing: storing the mode subjected to hash treatment into a hash table with the control state information character table used as an inlet; 2. taking a window starting with a character at any position of a text as a unit during mode matching process, sequentially carrying out hash processing on sub-windows in the current window, accessing the hash table through control state information of the character table, comparing the text in the sub-window with the mode with a specific hash value, and outputting the related information if matching is successful; and 3. sequentially scanning the text till the end of the text. The invention is suitable for a parallelized string matching algorithm with large mode data volume as well as centralized mode length, and can be applied to the technical field applying multi-mode string matching methods.

Description

technical field [0001] The invention relates to a multi-mode string matching algorithm based on scalable precision chaotic hash, belonging to the technical field of computer science. Background technique [0002] In the field of computer science, string matching algorithm is one of the important basic research fields. String matching is required in applications such as spell checking, machine translation, search engines, network intrusion detection, computer virus signature matching, and DNA sequence comparison and analysis. . [0003] The string matching problem refers to finding all occurrences of some special symbol sequences in a certain symbol sequence or text according to certain matching conditions. Multi-pattern string matching is mathematically defined as: [0004] (1) A limited set of characters or symbols ∑; [0005] (2) Pattern set P={P 1 , P 2 ,...,P m},in [0006] (3) The text is TEXT={t 1 , t 2 , t 3 , ..., t n}, t j ∈∑(1≤j≤n); [0007] Given a ...

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Problems solved by technology

[0012] (2) The chaotic system is extremely sensitive to the initial state, and a very small deviation of the initial condition will cause great differences in the results;

[0015] For the classical chaos theory, the chaos equation is defined in a continuous space; because the chaos is extremely sensitive to the initial state, under the limited precision of the computer, the introduction of quantization error makes the chaos deviate from the continuous track after many iterations, therefore, enter A cyclic state or a finite state, which leads to the degradation of the dynamical properties of the chaotic system, that is, the degradation of the chaotic properties

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