Issue #23: Add countingsort interface and documentation

crates/cs/blocks-cs-sort/src/algorithms.rs

@@ -1,5 +1,7 @@
 // Sorting algorithms
 pub mod quicksort;
+pub mod countingsort;
 
 // Re-export commonly used functions for convenience
-pub use self::quicksort::sort as quicksort;
+pub use self::quicksort::sort as quicksort;
+pub use self::countingsort::sort as countingsort;

crates/cs/blocks-cs-sort/src/algorithms/countingsort.rs

@@ -0,0 +1,41 @@
+use std::fmt::Debug;
+
+/// Counting Sort implementation for sorting slices of unsigned integers.
+/// 
+/// # Algorithm Overview
+/// Counting sort works by:
+/// 1. Finding the range of input data (min to max)
+/// 2. Counting the frequency of each value in the input range
+/// 3. Building the cumulative frequency array
+/// 4. Placing each element in its sorted position
+/// 
+/// # Time Complexity
+/// - Best Case: O(n + k) where k is the range of input
+/// - Average Case: O(n + k)
+/// - Worst Case: O(n + k)
+/// 
+/// # Space Complexity
+/// - O(k) auxiliary space where k is the range of input
+/// 
+/// # Stability
+/// - Stable sort algorithm
+/// 
+/// # Advantages
+/// - Linear time complexity when k = O(n)
+/// - Excellent for integers with known, limited range
+/// - Stable sorting algorithm
+/// - Can be used as a subroutine in radix sort
+/// 
+/// # Limitations
+/// - Only works with non-negative integers
+/// - Not efficient when the range of input values is much larger than n
+/// - Requires extra space proportional to the range of input
+pub fn sort(slice: &mut [u32]) {
+    // Implementation will be added later
+}
+
+/// Finds the maximum value in the slice
+fn find_max(slice: &[u32]) -> u32 {
+    // Implementation will be added later
+    0
+}