93 lines
1.8 KiB
Rust
93 lines
1.8 KiB
Rust
//! # Rational Numbers (fractions)
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//!
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//! Traits to implement:
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//! * Add
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//! * AddAssign
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//! * Div
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//! * DivAssign
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//! * Mul
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//! * MulAssign
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//! * Neg
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//! * Sub
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//! * SubAssign
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use crate::{Sign, Unsigned};
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use std::ops::{Mul, Neg};
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#[derive(Debug, Default, Copy, Clone, Eq, PartialEq)]
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pub struct Frac<T: Unsigned = usize> {
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numer: T,
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denom: T,
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sign: Sign,
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}
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impl<T: Unsigned> Frac<T> {
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/// Create a new rational number
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pub fn new(n: T, d: T) -> Self {
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if d.is_zero() {
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panic!("Fraction can not have a zero denominator");
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}
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Frac {
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numer: n,
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denom: d,
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sign: Sign::Positive,
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}
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.reduce()
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}
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pub fn new_neg(n: T, d: T) -> Self {
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let mut frac = Frac::new(n, d);
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frac.sign = Sign::Negative;
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frac
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}
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fn reduce(mut self) -> Self {
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let gcd = T::gcd(self.numer, self.denom);
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self.numer /= gcd;
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self.denom /= gcd;
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self
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}
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}
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macro_rules! impl_mul {
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($Type: ty) => {
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impl Mul for Frac<$Type> {
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type Output = Self;
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fn mul(self, rhs: Self) -> Self {
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let numer = self.numer * rhs.numer;
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let denom = self.denom * rhs.denom;
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// Figure out the sign
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if self.sign != rhs.sign {
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Self::new_neg(numer, denom)
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} else {
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Self::new(numer, denom)
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}
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}
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}
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};
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}
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impl_mul!(u8);
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impl_mul!(u16);
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impl_mul!(u32);
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impl_mul!(u64);
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impl_mul!(usize);
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impl<T: Unsigned> Neg for Frac<T> {
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type Output = Self;
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fn neg(self) -> Self::Output {
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let mut out = self.clone();
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out.sign = !self.sign;
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out
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}
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}
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#[cfg(test)]
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mod tests {}
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