### Abstract

The so called "four Russians technique" is often used to speed up algorithms by packing several data items in a single memory cell. Given a sequence of n symbols over a constant size alphabet, one can pack the sequence into O (n/λ) memory cells in O (log λ) time using n/log λ processors, where λ is the number of symbols packed into one memory word. Given a pattern of length m and a text of length n, this paper presents an efficient CRCW-PRAM string-matching algorithm for packed strings that takes O (log log (m/λ)) time and performs O (n/λ) operations for λ = O (log n), an improvement by a factor of λ on the number of operations used in previous algorithms. Using this string-matching algorithm one can test if a string is square-free and find all palindromes in a string in O (log log n) time using n/log log n processors.

Original language | English (US) |
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Pages (from-to) | 521-544 |

Number of pages | 24 |

Journal | Theoretical Informatics and Applications |

Volume | 30 |

Issue number | 6 |

DOIs | |

State | Published - Jan 1 1996 |

Externally published | Yes |

### ASJC Scopus subject areas

- Software
- Mathematics(all)
- Computer Science Applications

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## Cite this

*Theoretical Informatics and Applications*,

*30*(6), 521-544. https://doi.org/10.1051/ita/1996300605211