copy-paste problems

src/assignments/assignment07/small_exercises.rs

@@ -0,0 +1,119 @@
+//! Implement functions usint `Iterator` trait
+
+struct FindIter<'s, T: Eq> {
+    query: &'s [T],
+    base: &'s [T],
+    curr: usize,
+}
+
+impl<T: Eq> Iterator for FindIter<'_, T> {
+    type Item = usize;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}
+
+/// Returns an iterator over substring query indexes in the base.
+pub fn find<'s, T: Eq>(query: &'s [T], base: &'s [T]) -> impl 's + Iterator<Item = usize> {
+    FindIter {
+        query,
+        base,
+        curr: 0,
+    }
+}
+
+/// Implement fibonacci iterator
+struct FibIter<T> {
+    // TODO: remove `_marker` and add necessary fields as you want
+    _marker: std::marker::PhantomData<T>,
+}
+
+impl<T: std::ops::Add<Output = T> + Copy> FibIter<T> {
+    fn new(first: T, second: T) -> Self {
+        todo!()
+    }
+}
+
+impl<T> Iterator for FibIter<T>
+where
+    T: std::ops::Add<Output = T> + Copy,
+{
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}
+
+/// Returns and iterator over the generic fibonacci sequence starting from `first` and `second`.
+/// This is a generic version of `fibonacci` function, which works for any types that implements `std::ops::Add` trait.
+pub fn fib<T>(first: T, second: T) -> impl Iterator<Item = T>
+where
+    T: std::ops::Add<Output = T> + Copy,
+{
+    todo!("remove below");
+    std::iter::empty()
+}
+
+/// Endpoint of range, inclusive or exclusive.
+#[derive(Debug)]
+pub enum Endpoint {
+    /// Inclusive endpoint
+    Inclusive(isize),
+
+    /// Exclusive endpoint
+    Exclusive(isize),
+}
+
+struct RangeIter {
+    // TODO: add necessary fields as you want
+}
+
+impl RangeIter {
+    fn new(endpoints: (Endpoint, Endpoint), step: isize) -> Self {
+        todo!()
+    }
+}
+
+impl Iterator for RangeIter {
+    type Item = isize;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}
+
+/// Returns an iterator over the range [left, right) with the given step.
+pub fn range(left: Endpoint, right: Endpoint, step: isize) -> impl Iterator<Item = isize> {
+    todo!("remove below");
+    std::iter::empty()
+}
+
+/// Write an iterator that returns all divisors of n in increasing order.
+/// Assume n > 0.
+///
+/// Hint: trying all candidates from 1 to n will most likely time out!
+/// To optimize it, make use of the following fact:
+/// if x is a divisor of n that is greater than sqrt(n),
+/// then n/x is a divisor of n that is smaller than sqrt(n).
+struct Divisors {
+    n: u64,
+    // TODO: you may define additional fields here
+}
+
+impl Iterator for Divisors {
+    type Item = u64;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}
+
+/// Returns an iterator over the divisors of n.
+pub fn divisors(n: u64) -> impl Iterator<Item = u64> {
+    Divisors {
+        n,
+        // TODO: you may define additional fields here
+    }
+}