feat: make sorting mods consistent + misc minor fixes (#61)

Co-authored-by: Alexander González <[email protected]>

Cargo.toml

@@ -6,3 +6,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+paste = "1.0.12"

src/sorting/bogo_sort.rs

@@ -1,65 +1,76 @@
-use super::traits::MutableSorter;
 use crate::math::PCG32;
+use crate::sorting::traits::Sorter;
 use std::time::{SystemTime, UNIX_EPOCH};
 
-const DEFAULT: u64 = 4294967296;
+const DEFAULT: u64 = 2 << 31; // 2^32
 
-pub struct BogoSort;
+fn is_sorted<T: Ord>(arr: &[T], len: usize) -> bool {
+ if len <= 1 {
+ return true;
+ }
 
-impl BogoSort {
- fn is_sorted<T: Ord>(arr: &[T], len: usize) -> bool {
- for i in 0..len - 1 {
- if arr[i] > arr[i + 1] {
- return false;
- }
+ for i in 0..len - 1 {
+ if arr[i] > arr[i + 1] {
+ return false;
  }
-
- true
- }
- #[cfg(target_pointer_width = "64")]
- fn generate_index(range: usize, generator: &mut PCG32) -> usize {
- generator.get_u64() as usize % range
  }
 
- #[cfg(not(target_pointer_width = "64"))]
- fn generate_index(range: usize, generator: &mut PCG32) -> usize {
- generator.get_u32() as usize % range
+ true
+}
+#[cfg(target_pointer_width = "64")]
+fn generate_index(range: usize, generator: &mut PCG32) -> usize {
+ generator.get_u64() as usize % range
+}
+
+#[cfg(not(target_pointer_width = "64"))]
+fn generate_index(range: usize, generator: &mut PCG32) -> usize {
+ generator.get_u32() as usize % range
+}
+
+/**
+ * Fisher–Yates shuffle for generating random permutation.
+ */
+fn permute_randomly<T>(arr: &mut [T], len: usize, generator: &mut PCG32) {
+ if len <= 1 {
+ return;
  }
 
- /**
- * Fisher–Yates shuffle for generating random permutation.
- */
- fn permute_randomly<T>(arr: &mut [T], len: usize, generator: &mut PCG32) {
- for i in (1..len).rev() {
- let j = BogoSort::generate_index(i + 1, generator);
- arr.swap(i, j);
- }
+ for i in (1..len).rev() {
+ let j = generate_index(i + 1, generator);
+ arr.swap(i, j);
  }
 }
 
-impl<T> MutableSorter<T> for BogoSort {
- fn sort(arr: &mut [T])
- where
- T: Ord,
- {
- let seed = match SystemTime::now().duration_since(UNIX_EPOCH) {
- Ok(duration) => duration.as_millis() as u64,
- Err(_) => DEFAULT,
- };
+fn bogo_sort<T: Ord>(arr: &mut [T]) {
+ let seed = match SystemTime::now().duration_since(UNIX_EPOCH) {
+ Ok(duration) => duration.as_millis() as u64,
+ Err(_) => DEFAULT,
+ };
 
-  let mut random_generator = PCG32::new_default(seed);
+ let mut random_generator = PCG32::new_default(seed);
 
- let arr_length = arr.len();
- while !BogoSort::is_sorted(arr, arr_length) {
- BogoSort::permute_randomly(arr, arr_length, &mut random_generator);
- }
+ let arr_length = arr.len();
+ while !is_sorted(arr, arr_length) {
+ permute_randomly(arr, arr_length, &mut random_generator);
+ }
+}
+
+pub struct BogoSort;
+
+impl<T> Sorter<T> for BogoSort
+where
+ T: Ord + Copy,
+{
+ fn sort_inplace(arr: &mut [T]) {
+ bogo_sort(arr);
  }
 }
 
 #[cfg(test)]
 mod tests {
- use super::super::traits::MutableSorter;
- use super::BogoSort;
+ use crate::sorting::traits::Sorter;
+ use crate::sorting::BogoSort;
 
- sorting_tests!(BogoSort::sort, inplace);
+ sorting_tests!(BogoSort::sort, bogo_sort);
+ sorting_tests!(BogoSort::sort_inplace, bogo_sort, inplace);
 }

src/sorting/bubble_sort.rs

@@ -1,31 +1,37 @@
-// It sorts the array by repeatedly comparing the
-// adjacent elements and swapping them if they are
-// in the wrong order.
-// Time complexity is O(N^2)
-// Auxiliary space is O(1)
-use super::traits::MutableSorter;
+use crate::sorting::traits::Sorter;
 
-pub struct BubbleSort;
-
-impl<T> MutableSorter<T> for BubbleSort {
- fn sort(array: &mut [T])
- where
- T: Ord,
- {
- for i in 0..array.len() {
- // Last i elements are already in place.
- for j in 0..array.len() - 1 - i {
- if array[j] > array[j + 1] {
- array.swap(j, j + 1);
- }
+fn bubble_sort<T: Ord>(arr: &mut [T]) {
+ for i in 0..arr.len() {
+ // Last i elements are already in place.
+ for j in 0..arr.len() - 1 - i {
+ if arr[j] > arr[j + 1] {
+ arr.swap(j, j + 1);
  }
  }
  }
 }
 
+/// It sorts the array by repeatedly comparing the
+/// adjacent elements and swapping them if they are
+/// in the wrong order.
+/// Time complexity is O(N^2)
+/// Auxiliary space is O(1)
+pub struct BubbleSort;
+
+impl<T> Sorter<T> for BubbleSort
+where
+ T: Ord + Copy,
+{
+ fn sort_inplace(array: &mut [T]) {
+ bubble_sort(array);
+ }
+}
+
 #[cfg(test)]
 mod tests {
- use super::super::traits::MutableSorter;
- use super::BubbleSort;
- sorting_tests!(BubbleSort::sort, inplace);
+ use crate::sorting::traits::Sorter;
+ use crate::sorting::BubbleSort;
+
+ sorting_tests!(BubbleSort::sort, bubble_sort);
+ sorting_tests!(BubbleSort::sort_inplace, bubble_sort, inplace);
 }

src/sorting/bucket_sort.rs

@@ -1,61 +1,54 @@
-/// Sort a slice using bucket sort algorithm.
-///
-/// Time complexity is `O(n + k)` on average, where `n` is the number of elements,
-/// `k` is the number of buckets used in process.
-///
-/// Space complexity is `O(n + k)`, as it sorts not in-place.
-pub fn bucket_sort(arr: &[usize]) -> Vec<usize> {
+use crate::sorting::insertion_sort::InsertionSort;
+use crate::sorting::traits::Sorter;
+
+fn bucket_sort<T: Ord + Copy + Into<usize>>(arr: &mut [T]) {
  if arr.is_empty() {
- return vec![];
+ return;
  }
 
  let max = *arr.iter().max().unwrap();
  let len = arr.len();
  let mut buckets = vec![vec![]; len + 1];
 
- for x in arr {
- buckets[len * *x / max].push(*x);
+ for x in arr.iter() {
+ buckets[len * (*x).into() / max.into()].push(*x);
  }
 
  for bucket in buckets.iter_mut() {
- super::insertion_sort(bucket);
+ InsertionSort::sort_inplace(bucket);
  }
 
- let mut result = vec![];
+ let mut i = 0;
  for bucket in buckets {
  for x in bucket {
- result.push(x);
+ arr[i] = x;
+ i += 1;
  }
  }
+}
 
- result
+/// Sort a slice using bucket sort algorithm.
+///
+/// Time complexity is `O(n + k)` on average, where `n` is the number of elements,
+/// `k` is the number of buckets used in process.
+///
+/// Space complexity is `O(n + k)`, as it sorts not in-place.
+pub struct BucketSort;
+
+impl<T> Sorter<T> for BucketSort
+where
+ T: Ord + Copy + Into<usize>,
+{
+ fn sort_inplace(arr: &mut [T]) {
+ bucket_sort(arr);
+ }
 }
 
 #[cfg(test)]
 mod tests {
- use super::super::is_sorted;
- use super::*;
-
- sorting_tests!(bucket_sort);
+ use crate::sorting::traits::Sorter;
+ use crate::sorting::BucketSort;
 
- #[test]
- fn empty() {
- let arr: [usize; 0] = [];
- let res = bucket_sort(&arr);
- assert!(is_sorted(&res));
- }
-
- #[test]
- fn one_element() {
- let arr: [usize; 1] = [4];
- let res = bucket_sort(&arr);
- assert!(is_sorted(&res));
- }
-
- #[test]
- fn odd_number_of_elements() {
- let arr: Vec<usize> = vec![1, 21, 5, 11, 58];
- let res = bucket_sort(&arr);
- assert!(is_sorted(&res));
- }
+ sorting_tests!(BucketSort::sort, bucket_sort);
+ sorting_tests!(BucketSort::sort_inplace, bucket_sort, inplace);
 }

src/sorting/cocktail_shaker_sort.rs

@@ -1,4 +1,6 @@
-pub fn cocktail_shaker_sort<T: Ord>(arr: &mut [T]) {
+use crate::sorting::traits::Sorter;
+
+fn cocktail_shaker_sort<T: Ord>(arr: &mut [T]) {
  let len = arr.len();
 
  if len == 0 {
@@ -34,23 +36,26 @@ pub fn cocktail_shaker_sort<T: Ord>(arr: &mut [T]) {
  }
 }
 
-#[cfg(test)]
-mod tests {
- use super::*;
-
- sorting_tests!(cocktail_shaker_sort, inplace);
+pub struct CocktailShakerSort;
 
- #[test]
- fn empty() {
- let mut arr = Vec::<i32>::new();
- cocktail_shaker_sort(&mut arr);
- assert_eq!(arr, vec![]);
+impl<T> Sorter<T> for CocktailShakerSort
+where
+ T: Ord + Copy,
+{
+ fn sort_inplace(arr: &mut [T]) {
+ cocktail_shaker_sort(arr);
  }
+}
 
- #[test]
- fn one_element() {
- let mut arr = vec![1];
- cocktail_shaker_sort(&mut arr);
- assert_eq!(arr, vec![1]);
- }
+#[cfg(test)]
+mod tests {
+ use crate::sorting::traits::Sorter;
+ use crate::sorting::CocktailShakerSort;
+
+ sorting_tests!(CocktailShakerSort::sort, cocktail_shaker_sort);
+ sorting_tests!(
+ CocktailShakerSort::sort_inplace,
+ cocktail_shaker_sort,
+ inplace
+ );
 }