### 6 releases

Uses old Rust 2015

0.1.5 | Nov 25, 2017 |
---|---|

0.1.4 | Nov 21, 2017 |

#**4** in #substring-search

**304** downloads per month

Used in **3** crates

**MIT/Apache**

37KB

714 lines

General string search in constant space, linear time, for nonorderable alphabets. Also known as exact string matching.

In Rust terms this means we can define the function:

`fn` `gs_find``<`T`:` `Eq``>``(``text``:` `&`[T], `pattern``:` `&`[T]`)`` ``->` `Option``<``usize``>` `{`
`//` ...
`}`

and the function computes in **O(n)** time and **O(1)** space.
In the worst case, this algorithm makes **4 n** character comparisons.

Note that the Crochemore-Perrin (“Two Way” algorithm) is much superior if there is a linear order for the alphabet.

This work is Copyright 2017 by Ulrik Sverdrup "bluss"; see license terms in the package.

# References

Both papers are recommended reading. The comments in this crate’s implementation are also meant to explain and point out important details, so that’s recommended reading too.

- [GS] Z. Galil and J. Seiferas,
*Time-Space-Optimal String Matching*, Journal of Computer and System Sciences (1983) - [CR] M. Crochemore and W. Rytter,
*Squares, Cubes, and Time-Space Efficient String Searching*, Algorithmica (1995)

#### Dependencies

~22KB