## red_primality

red_primality provides zero-setup primality testing and factoring for all u64

### 8 releases

 0.2.0 Jan 2, 2020 Aug 30, 2019

#1499 in Math

24 downloads per month

LGPL-3.0

28KB
702 lines

red_primality provides a quick accurate primality test for all u64.

# Example

``````use red_primality::is_u64_prime;

fn main() {
assert!(is_u64_prime(5));
assert!(!is_u64_prime(6));
}
``````

### `lib.rs`:

red_primality provides zero-setup primality testing and factoring for all u64

# Example

``````use red_primality::{ is_u64_prime, factor, Prime, euler_totient, mobius };

fn main() {
// Primality testing
assert!(is_u64_prime(5));
assert!(!is_u64_prime(6));

// Factoring a near-worst-case semiprime
let facs: Vec<(Prime, u64)> = factor(18302912619494838287).iter().collect();
let p1 = Prime::new(4278190337).unwrap();
let p2 = Prime::new(4278190351).unwrap();
assert_eq!(facs, vec![(p1, 1), (p2, 1)]);

// Euler's totient function
assert_eq!(euler_totient(180), (1*2) * (2*3) * (4));

// mobius(x,y) is the Möbius function of the ratio x/y
assert_eq!(mobius(90, 2), 0);  // 90/2 = 45, contiains 3^2
assert_eq!(mobius(90, 3), -1);  // 90/3 = 30 = 2*3*5, so -1
assert_eq!(mobius(90, 6), 1);  // 90/6 = 15 = 3*5, so +1
}
``````

~475KB