use_arithmetic/
gcd.rs

1/// Computes the greatest common divisor of two unsigned integers.
2///
3/// This helper uses the Euclidean algorithm and keeps the required edge cases
4/// explicit: `gcd(0, 0) == 0` and `gcd(a, 0) == a`.
5///
6/// # Examples
7///
8/// ```rust
9/// use use_arithmetic::gcd;
10///
11/// assert_eq!(gcd(54, 24), 6);
12/// assert_eq!(gcd(0, 0), 0);
13/// assert_eq!(gcd(21, 0), 21);
14/// ```
15#[must_use]
16pub const fn gcd(mut left: u64, mut right: u64) -> u64 {
17    while right != 0 {
18        let remainder = left % right;
19        left = right;
20        right = remainder;
21    }
22
23    left
24}
25
26#[cfg(test)]
27mod tests {
28    use super::gcd;
29
30    #[test]
31    fn handles_zero_and_positive_cases() {
32        assert_eq!(gcd(0, 0), 0);
33        assert_eq!(gcd(21, 0), 21);
34        assert_eq!(gcd(0, 21), 21);
35        assert_eq!(gcd(54, 24), 6);
36        assert_eq!(gcd(48, 18), 6);
37    }
38}
use_arithmetic/gcd.rs

use_arithmetic/
gcd.rs
