use crate::math::Math;
pub struct Frac {
pub num: i64,
pub den: i64,
}
impl Frac {
pub fn new(num: i64, den: i64) -> Result<Self, String> {
if den==0 {
return Err("\"den\" must not be 0".into())
}
Ok(Self { num, den })
}
pub fn to_dec(self) -> f64 {
(self.num / self.den) as f64
}
pub fn normalize(mut self) -> Self {
if self.num==0 {
return Self { num:0, den: 1 };
}
if self.den < 0 {
self.num = -self.num;
self.den = -self.den;
}
let gcd = Math::gcd(self.den, self.num);
Self {
num: self.num / gcd,
den: self.den / gcd
}
}
pub fn reverse(self) -> Result<Self, String> {
if self.num==0 {
return Err("division by zero (reciprocal of 0)".into())
}
Self::new(self.den, self.num)
}
pub fn add(self, other: Self) -> Self {
let num = self.num * other.den + self.den * other.num;
let den = self.den * other.den;
Self { num, den }.normalize()
}
pub fn min(self, other: Self) -> Self {
let num = self.num * other.den - self.den * other.num;
let den = self.den * other.den;
Self { num, den }.normalize()
}
pub fn mul(self, other: Self) -> Self {
let num = self.num * other.num;
let den = self.den * other.den;
Self { num, den }.normalize()
}
pub fn div(self, other: Self) -> Self {
let num = self.num * other.den;
let den = self.den * other.num;
Self { num, den }.normalize()
}
}