CON-3667 Review All Rust Checkpoints Exercises

solutions/brain_fuck/Cargo.toml

@@ -2,7 +2,7 @@
 name = "brain_fuck"
 version = "0.1.0"
 authors = ["OGordoo <marcosafonso8@hotmail.com>"]
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/brain_fuck/src/main.rs

@@ -1,56 +1,61 @@
-pub fn brainfuck(pattern: &str) {
-    let mut ds = vec![0 as i8; 5000];
-    let mut dp: usize = 0;
+const STACK_MEM: usize = 2048;
 
-    let pattern_arr = pattern.chars().collect::<Vec<char>>();
-
-    let mut i: i32 = 0;
-
-    if pattern_arr.len() == 0 {
+pub fn brainfuck(code: &str) {
+    if code.is_empty() {
         return;
     }
-    while i as usize <= (&pattern_arr).len() - 1 {
-        match &pattern_arr[i as usize] {
-            '>' => dp += 1,
-            '<' => dp -= 1,
-            '+' => ds[dp] = ds[dp] + 1,
-            '-' => ds[dp] = ds[dp] - 1,
-            '.' => {
-                print!("{}", ds[dp] as u8 as char);
+
+    let mut mem = [0i8; STACK_MEM];
+    let mut mp = 0;
+    let code = code.as_bytes();
+    let jumps = build_jumps(code);
+    let mut ip = 0;
+
+    while ip < code.len() {
+        match code[ip] {
+            b'>' => mp = (mp + 1) % STACK_MEM,
+            b'<' => mp = (mp + STACK_MEM - 1) % STACK_MEM,
+            b'+' => mem[mp] = mem[mp].wrapping_add(1),
+            b'-' => mem[mp] = mem[mp].wrapping_sub(1),
+            b'.' => print!("{}", mem[mp] as u8 as char),
+            b'[' => {
+                if mem[mp] == 0 {
+                    ip = jumps[ip]
+                }
             }
-            '[' => {
-                if ds[dp] == 0 {
-                    let mut nc = 1;
-                    while nc > 0 {
-                        i += 1;
-                        if pattern_arr[i as usize] == '[' {
-                            nc += 1;
-                        } else if pattern_arr[i as usize] == ']' {
-                            nc -= 1;
-                        }
-                    }
+            b']' => {
+                if mem[mp] != 0 {
+                    ip = jumps[ip]
                 }
             }
-            ']' => {
-                if ds[dp] != 0 {
-                    let mut nc = 1;
-                    while nc > 0 {
-                        i -= 1;
-                        if pattern_arr[i as usize] == ']' {
-                            nc += 1;
-                        } else if pattern_arr[i as usize] == '[' {
-                            nc -= 1;
-                        }
-                    }
+            _ => (),
+        }
+        ip += 1;
+    }
+}
+
+fn build_jumps(code: &[u8]) -> Vec<usize> {
+    let mut jumps = vec![0; code.len()];
+    let mut stack = Vec::new();
+
+    for (i, &b) in code.iter().enumerate() {
+        match b {
+            b'[' => stack.push(i),
+            b']' => {
+                if let Some(start) = stack.pop() {
+                    jumps[start] = i;
+                    jumps[i] = start;
                 }
             }
-            _ => {}
+            _ => (),
         }
-        i += 1;
     }
+
+    jumps
 }
 
 fn main() {
-    let args: Vec<String> = std::env::args().collect();
-    brainfuck(&args[1]);
+    if let Some(arg) = std::env::args().nth(1) {
+        brainfuck(&arg);
+    }
 }

solutions/check_user_name/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "check_user_name"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/check_user_name/src/lib.rs

@@ -10,22 +10,22 @@ pub struct User {
 }
 
 impl User {
-    pub fn new(user: String, access_level: AccessLevel) -> User {
-        User {
+    pub const fn new(user: String, access_level: AccessLevel) -> Self {
+        Self {
             access_level,
             name: user,
         }
     }
 
-    pub fn send_name(&self) -> Option<&str> {
-        match &self.access_level {
+    pub const fn send_name(&self) -> Option<&str> {
+        match self.access_level {
             AccessLevel::Guest => None,
-            _ => Some(&self.name),
+            _ => Some(self.name.as_str()),
         }
     }
 }
 
-pub fn check_user_name(user: &User) -> (bool, &str) {
+pub const fn check_user_name(user: &User) -> (bool, &str) {
     match user.send_name() {
         Some(name) => (true, name),
         None => (false, "ERROR: User is guest"),

solutions/drop_the_blog/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "drop_the_blog"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/drop_the_blog/src/lib.rs

@@ -7,20 +7,23 @@ pub struct Blog {
 }
 
 impl Blog {
-    pub fn new() -> Blog {
-        Blog::default()
+    #[inline]
+    pub fn new() -> Self {
+        Default::default()
     }
 
-    pub fn new_article(&self, body: String) -> (usize, Article) {
+    pub fn new_article(&self, body: String) -> (usize, Article<'_>) {
         let new_article = Article::new(self.new_id(), body, self);
         self.states.borrow_mut().push(false);
         (new_article.id, new_article)
     }
 
+    #[inline]
     pub fn new_id(&self) -> usize {
-        self.states.borrow().len()
+        self.states.borrow().len() // const when borrow is stabilised
     }
 
+    #[inline]
     pub fn is_dropped(&self, id: usize) -> bool {
         self.states.borrow()[id]
     }
@@ -30,7 +33,7 @@ impl Blog {
             panic!("{} is already dropped", id)
         }
         self.states.borrow_mut()[id] = true;
-        self.drops.set(self.drops.get() + 1);
+        self.drops.update(|x| x + 1);
     }
 }
 
@@ -42,16 +45,15 @@ pub struct Article<'a> {
 }
 
 impl<'a> Article<'a> {
-    pub fn new(id: usize, body: String, parent: &'a Blog) -> Article {
-        Article { id, body, parent }
+    pub const fn new(id: usize, body: String, parent: &'a Blog) -> Self {
+        Self { id, body, parent }
     }
 
-    pub fn discard(self) {
-        drop(self);
-    }
+    #[inline]
+    pub fn discard(self) {}
 }
 
-impl<'a> Drop for Article<'a> {
+impl Drop for Article<'_> {
     fn drop(&mut self) {
         self.parent.add_drop(self.id);
     }

solutions/flat_tree/Cargo.toml

@@ -2,7 +2,7 @@
 name = "flat_tree"
 version = "0.1.0"
 authors = ["Augusto <aug.ornelas@gmail.com>"]
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/flat_tree/src/lib.rs

@@ -1,27 +1,6 @@
-// convert a binary search tree into a sorted array
-
 use std::collections::BTreeSet;
 
-#[allow(dead_code)]
+#[inline]
 pub fn flatten_tree<T: ToOwned<Owned = T>>(tree: &BTreeSet<T>) -> Vec<T> {
-    let mut flat = Vec::new();
-    for v in tree {
-        flat.push(v.to_owned());
-    }
-    flat
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let mut tree = BTreeSet::new();
-        tree.insert(3);
-        tree.insert(0);
-        tree.insert(9);
-        tree.insert(10);
-        assert_eq!(flatten_tree(&tree), &[0, 3, 9, 10]);
-    }
+    tree.iter().map(T::to_owned).collect()
 }

solutions/insertion_sort/Cargo.toml

@@ -2,7 +2,7 @@
 name = "insertion_sort"
 version = "0.1.0"
 authors = ["Augusto <aug.ornelas@gmail.com>"]
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/insertion_sort/src/lib.rs

@@ -1,58 +1,10 @@
-// How to avoid that students use sort without creating a program to
-// restrict functions in the code??
-// Just use a grep?
-// Implement the insertion sort algorithm but implement it in a step
-// by step so we can test that each step is corresponding with the algorithm
+pub fn insertion_sort(slice: &mut [i32], steps: usize) {
+    for i in 1..=steps.min(slice.len().saturating_sub(1)) {
+        let mut j = i;
 
-// Insertion sort algorithmAlgorithm
-
-// To sort an array of size n in ascending order:
-
-// 1: Iterate from arr[1] to arr[n] over the array.
-
-// 2: Compare the current element (key) to its predecessor.
-
-// 3: If the key element is smaller than its predecessor, compare it
-// to the elements before. Move the greater elements one position up
-// to make space for the swapped element.
-
-pub fn insertion_sort<T: Ord + Clone>(ar: &mut [T], steps: usize) {
-    assert!(steps > 0);
-    for i in 1..steps + 1 {
-        let key = ar[i].to_owned();
-        let mut j: i32 = i as i32 - 1;
-        while j >= 0 && key < ar[j as usize] {
-            // move the value to the next position
-            ar[(j + 1) as usize] = ar[j as usize].to_owned();
+        while j > 0 && slice[j] < slice[j - 1] {
+            slice.swap(j, j - 1);
             j -= 1;
         }
-        ar[(j + 1) as usize] = key
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
-        let len = target.len();
-        insertion_sort(&mut target, len - 1);
-        assert_eq!(&[1, 2, 3, 4, 5, 6, 7, 8], &target);
-    }
-
-    #[test]
-    fn test_first_step() {
-        let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
-        insertion_sort(&mut target, 1);
-        assert_eq!(&[3, 5, 7, 2, 1, 6, 8, 4], &target);
-    }
-
-    #[test]
-    fn test_second_step() {
-        let mut target = [5, 3, 7, 2, 1, 6, 8, 4];
-        insertion_sort(&mut target, 2);
-        assert_eq!(&[3, 5, 7, 2, 1, 6, 8, 4], &target);
     }
 }

solutions/inv_pyramid/Cargo.toml

@@ -2,7 +2,7 @@
 name = "inv_pyramid"
 version = "0.1.0"
 authors = ["lee <lee-dasilva@hotmail.com>"]
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

solutions/inv_pyramid/src/lib.rs

@@ -1,29 +1,7 @@
-// In general it's better to use `usize` rather than `u32` for variables that represent
-// addressable memory. Like the index or length of a vector, slice or string
+#[inline]
 pub fn inv_pyramid(st: String, max: usize) -> Vec<String> {
-    // Vec::with_capacity() creates a buffer with the size that
-    // we define. This makes the first operation be more costly because it
-    // allocates the memory at that moment but make the push calls more efficient
-    // because it avoids extra allocation
-    // It's good to use it if you know the final length of
-    // the vector
-    let mut vec = Vec::with_capacity(2 * max);
-    // In truth the length of the vector will always be ( 2*max - 1 ) at the
-    // end, but it doesn't make a lot of difference to allocate an
-    // extra element and that way I don't have to handle the case
-    // where max == 0 which cause a subtraction in overflow
-
-    // Pushes a string with `amount` number of spaces and the string
-    // `st` repeated `amount` number of times
-    let mut create_line = |amount| vec.push(format!("{:>1$}", st.repeat(amount), 2 * amount));
-
-    for amount in 1..max + 1 {
-        create_line(amount)
-    }
-
-    // the `rev` method reverses the range
-    for amount in (1..max).rev() {
-        create_line(amount)
-    }
-    return vec;
+    (1..=max)
+        .chain((1..max).rev())
+        .map(|i| format!("{:>1$}", st.repeat(i), 2 * i))
+        .collect()
 }

solutions/nextprime/Cargo.toml

@@ -2,7 +2,7 @@
 name = "nextprime"
 version = "0.1.0"
 authors = ["OGordoo <marcosafonso8@hotmail.com>"]
-edition = "2021"
+edition = "2024"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html