### 5 releases

✓ Uses Rust 2018 edition

0.2.2 | Oct 19, 2019 |
---|---|

0.2.1 | Oct 18, 2019 |

0.1.3 | Oct 15, 2019 |

0.1.1 | Oct 15, 2019 |

0.1.0 | Oct 15, 2019 |

#**152** in Math

**116** downloads per month

**MIT**license

10KB

194 lines

# prime_tools

This util provides a few tools for working with prime numbers.

Mostly for personal use with project euler problems. :)

`fn` `get_primes_less_than_x``(``x``:` `u32``)`` ``->` `Vec``<``u32``>`

Generates an ordered list of prime numbers from 2 up to x (exclusive).

Uses the sieve of Eratosthenes under the covers.

`fn` `get_prime_factors_with_counts``(``x``:` `u32`, `primes``:` `&``Vec``<``u32``>``)`` ``->` `HashMap``<``u32`, `u32``>`

To be used in conjunction with get_primes_less_than_x. Be sure to pass in

`at least up to sqrt(x).`

primes

`fn` `is_u32_prime``(``x``:` `u32``)`` ``->` `bool`

Figures out if x is prime. This is fast! I've benchmarked it at 2.7 seconds to process 1 million random

`s.`

u32

`fn` `is_u64_prime``(``x``:` `u32``)`` ``->` `bool`

Figures out if x is prime. This is pretty slow: I've benchmarked it at 26 seconds to process only 200 random

`s. :(`

u64

#### Dependencies

~480KB