Function greatest_common_divisor 

pub fn greatest_common_divisor(a: usize, b: usize) -> usize

Returns the greatest common divisor of a and b.

See wikipedia for more information.

Panics

Panics in debug mode if a == 0 && b == 0.

Examples

assert_eq!(greatest_common_divisor(2, 3), 1);
assert_eq!(greatest_common_divisor(5, 1), 1);
assert_eq!(greatest_common_divisor(5, 5), 5);
assert_eq!(greatest_common_divisor(12, 8), 4);
assert_eq!(greatest_common_divisor(12, 18), 6);