partition refactored

Author: deeper-x

sort/partition.go

@@ -0,0 +1,36 @@
+package sort
+
+import "github.com/deeper-x/data_struct_algs/constraints"
+
+// / Partition rearranges the elements of arr[low:high] around a pivot.
+// / It ensures that elements less than or equal to the pivot are on the left,
+// / and elements greater than the pivot are on the right. The pivot is chosen
+// / as the last element in the range.
+// /
+// / Parameters:
+// /   - arr []T: A slice of ordered elements.
+// /   - low, high int: The indices defining the subarray to partition.
+// /
+// / Returns:
+// /   - int: The final index of the pivot after partitioning.
+func Partition[T constraints.Ordered](arr []T, low, high int) int {
+	/// Index to track the correct position for smaller elements
+	index := low - 1
+
+	/// Choosing the pivot as the last element
+	pivotElement := arr[high]
+
+	/// Iterate through the array, moving smaller elements to the left
+	for i := low; i < high; i++ {
+		if arr[i] <= pivotElement {
+			index += 1
+			arr[index], arr[i] = arr[i], arr[index] /// Swap to move smaller element
+		}
+	}
+
+	/// Swap pivot into its correct position
+	arr[index+1], arr[high] = arr[high], arr[index+1]
+
+	/// Return the final pivot index
+	return index + 1
+}

sort/quicksort.go

@@ -1,3 +1,11 @@
+package sort
+
+import (
+	"math/rand"
+
+	"github.com/deeper-x/data_struct_algs/constraints"
+)
+
 // quicksort.go
 // description: Implementation of in-place quicksort algorithm
 // details:
@@ -7,14 +15,6 @@
 // space complexity: O(log n)
 // see sort_test.go for a test implementation, test function TestQuickSort.
 
-package sort
-
-import (
-	"math/rand"
-
-	"github.com/deeper-x/data_struct_algs/constraints"
-)
-
 func Quicksort[T constraints.Ordered](arr []T) []T {
 	if len(arr) < 2 {
 		return arr