update quicksort

Author: deeper-x

sort/quicksort.go

@@ -6,37 +6,44 @@ import (
 	"github.com/deeper-x/data_struct_algs/constraints"
 )
 
-// quicksort.go
-// description: Implementation of in-place quicksort algorithm
-// details:
-// A simple in-place quicksort algorithm implementation. [Wikipedia](https://en.wikipedia.org/wiki/Quicksort)
-// worst time complexity: O(n^2)
-// average time complexity: O(n log n)
-// space complexity: O(log n)
-// see sort_test.go for a test implementation, test function TestQuickSort.
-
+// / Quicksort sorts an array using the quicksort algorithm.
+// / It selects a pivot, partitions the array, and recursively sorts the subarrays.
+// /
+// / Parameters:
+// /   - arr []T: A slice of ordered elements to be sorted.
+// /
+// / Returns:
+// /   - []T: The sorted slice.
 func Quicksort[T constraints.Ordered](arr []T) []T {
+	/// Base case: If the array has 0 or 1 element, it's already sorted.
 	if len(arr) < 2 {
 		return arr
 	}
 
+	/// Initialize pointers for partitioning
 	left, right := 0, len(arr)-1
 
+	/// Select a random pivot index
 	pivot := rand.Int() % len(arr)
 
+	/// Move pivot element to the end of the array
 	arr[pivot], arr[right] = arr[right], arr[pivot]
 
+	/// Partitioning: Move elements smaller than pivot to the left side
 	for i := range arr {
-		if arr[i] < arr[right] {
-			arr[left], arr[i] = arr[i], arr[left]
+		if arr[i] < arr[right] { /// Compare with pivot element
+			arr[left], arr[i] = arr[i], arr[left] /// Swap smaller element to the left
 			left++
 		}
 	}
 
+	/// Place the pivot element in its correct position
 	arr[left], arr[right] = arr[right], arr[left]
 
-	Quicksort(arr[:left])
-	Quicksort(arr[left+1:])
+	/// Recursively apply Quicksort to the left and right subarrays
+	Quicksort(arr[:left])   /// Sort elements before pivot
+	Quicksort(arr[left+1:]) /// Sort elements after pivot
 
+	/// Return the sorted array
 	return arr
 }