use std::num::Int;
#[inline]
pub fn div_rem<T: Int>(a: T, b: T) -> (T, T) {
(a / b, a % b)
}
#[inline]
pub fn mod_floor<T: Int>(a: T, b: T) -> T {
let zero = Int::zero();
match a % b {
r if (r > zero && b < zero) || (r < zero && b > zero) => r + b,
r => r,
}
}
#[inline]
pub fn div_mod_floor<T: Int>(a: T, b: T) -> (T, T) {
let zero = Int::zero();
let one = Int::one();
match (a / b, a % b) {
(d, r) if (r > zero && b < zero) || (r < zero && b > zero) => (d - one, r + b),
(d, r) => (d, r),
}
}
#[cfg(test)]
mod tests {
use super::{mod_floor, div_mod_floor};
#[test]
fn test_mod_floor() {
assert_eq!(mod_floor( 8i, 3), 2);
assert_eq!(mod_floor( 8i, -3), -1);
assert_eq!(mod_floor(-8i, 3), 1);
assert_eq!(mod_floor(-8i, -3), -2);
assert_eq!(mod_floor( 1i, 2), 1);
assert_eq!(mod_floor( 1i, -2), -1);
assert_eq!(mod_floor(-1i, 2), 1);
assert_eq!(mod_floor(-1i, -2), -1);
}
#[test]
fn test_div_mod_floor() {
assert_eq!(div_mod_floor( 8i, 3), ( 2, 2));
assert_eq!(div_mod_floor( 8i, -3), (-3, -1));
assert_eq!(div_mod_floor(-8i, 3), (-3, 1));
assert_eq!(div_mod_floor(-8i, -3), ( 2, -2));
assert_eq!(div_mod_floor( 1i, 2), ( 0, 1));
assert_eq!(div_mod_floor( 1i, -2), (-1, -1));
assert_eq!(div_mod_floor(-1i, 2), (-1, 1));
assert_eq!(div_mod_floor(-1i, -2), ( 0, -1));
}
}