copy-paste problems

src/assignments/assignment06/semiring.rs

@@ -0,0 +1,168 @@
+//! Semiring
+
+use std::{collections::HashMap, fmt::Debug};
+
+/// Semiring.
+///
+/// Consult <https://en.wikipedia.org/wiki/Semiring>.
+pub trait Semiring: Debug + Clone + PartialEq {
+    /// Additive identity.
+    fn zero() -> Self;
+    /// Multiplicative identity.
+    fn one() -> Self;
+    /// Addition operation.
+    fn add(&self, rhs: &Self) -> Self;
+    /// Multiplication operation.
+    fn mul(&self, rhs: &Self) -> Self;
+}
+
+/// Converts integer to semiring value.
+pub fn from_usize<T: Semiring>(value: usize) -> T {
+    let mut result = T::zero();
+    let one = T::one();
+
+    for _ in 0..value {
+        result = T::add(&result, &one);
+    }
+
+    result
+}
+
+impl Semiring for u64 {
+    fn zero() -> Self {
+        todo!()
+    }
+
+    fn one() -> Self {
+        todo!()
+    }
+
+    fn add(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+
+    fn mul(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+}
+
+impl Semiring for i64 {
+    fn zero() -> Self {
+        todo!()
+    }
+
+    fn one() -> Self {
+        todo!()
+    }
+
+    fn add(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+
+    fn mul(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+}
+
+impl Semiring for f64 {
+    fn zero() -> Self {
+        todo!()
+    }
+
+    fn one() -> Self {
+        todo!()
+    }
+
+    fn add(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+
+    fn mul(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+}
+
+/// Polynomials with coefficient in `C`.
+///
+/// For example, polynomial `x^2 + 5x + 6` is represented in `Polynomial<u64>` as follows:
+///
+/// ```ignore
+/// Polynomial {
+///     coefficients: {
+///         2: 1,
+///         1: 5,
+///         0: 6,
+///     },
+/// }
+/// ```
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Polynomial<C: Semiring> {
+    coefficients: HashMap<u64, C>,
+}
+
+impl<C: Semiring> Semiring for Polynomial<C> {
+    fn zero() -> Self {
+        todo!()
+    }
+
+    fn one() -> Self {
+        todo!()
+    }
+
+    fn add(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+
+    fn mul(&self, rhs: &Self) -> Self {
+        todo!()
+    }
+}
+
+impl<C: Semiring> Polynomial<C> {
+    /// Constructs polynomial `x`.
+    pub fn x() -> Self {
+        todo!()
+    }
+
+    /// Evaluates the polynomial with the given value.
+    pub fn eval(&self, value: C) -> C {
+        todo!()
+    }
+
+    /// Constructs polynomial `ax^n`.
+    pub fn term(a: C, n: u64) -> Self {
+        todo!()
+    }
+}
+
+impl<C: Semiring> From<C> for Polynomial<C> {
+    fn from(value: C) -> Self {
+        todo!()
+    }
+}
+
+/// Given a string `s`, parse it into a `Polynomial<C>`.
+/// You may assume that `s` follows the criteria below.
+/// Therefore, you do not have to return `Err`.
+///
+/// Assumptions:
+/// - Each term is separated by ` + `.
+/// - Each term is one of the following form:
+///   `a`, `x`, `ax`, `x^n`, and `ax^n`,
+///   where `a` is a `usize` number and `n` is a `u64` number.
+///   This `a` should then be converted to a `C` type.
+/// - In `a`, it is guaranteed that `a >= 1`.
+/// - In `ax` and `ax^n`, it is guaranteed that `a >= 2`.
+/// - In `x^n` and `ax^n`, it is guaranteed that `n >= 2`.
+/// - All terms have unique degrees.
+///
+/// Consult `assignment06_jaemin_choi_grade.rs` for example valid strings.
+///
+/// Hint: `.split`, `.parse`, and `Polynomial::term`
+impl<C: Semiring> std::str::FromStr for Polynomial<C> {
+    type Err = (); // Ignore this for now...
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        todo!()
+    }
+}