Imports System
Module Program
''' <summary>
''' Swaps two integer values in place using pass-by-reference.
''' </summary>
Private Sub Swap(ByRef a As Integer, ByRef b As Integer)
Dim temp As Integer = a
a = b
b = temp
End Sub
''' <summary>
''' Sorts an integer array in non-decreasing order using Gnome Sort.
'''
''' Algorithm Logic (Single Loop):
''' - Advances through the array using a single while loop index.
''' - Moves forward when adjacent elements are in correct relative order.
''' - When an out-of-order adjacent pair is encountered, swaps the elements
''' and steps backward one index to verify order against preceding items.
''' - Time Complexity: O(N) best case (already sorted), O(N^2) worst case.
''' - Space Complexity: O(1) auxiliary space.
''' </summary>
''' <param name="arr">The array of integers to sort in place.</param>
Public Sub SingleLoopSort(arr As Integer())
Dim len AS Integer = arr.Length
If arr Is Nothing OrElse len <= 1 Then
Return
End If
Dim pos As Integer = 0
While pos < len
' Move forward if at the start or if the current pair is sorted
If pos = 0 OrElse arr(pos) >= arr(pos - 1) Then
pos += 1
Else
' Swap adjacent out-of-order elements and step backward
Swap(arr(pos), arr(pos - 1))
pos -= 1
End If
End While
End Sub
Sub Main()
Dim numbers As Integer() = {42, -5, 12, 0, 89, -18, 33, 7}
Console.WriteLine("Original array:")
Console.WriteLine(String.Join(" ", numbers))
SingleLoopSort(numbers)
Console.WriteLine()
Console.WriteLine("Sorted array:")
Console.WriteLine(String.Join(" ", numbers))
End Sub
End Module
' run:
'
' Original array:
' 42 -5 12 0 89 -18 33 7
'
' Sorted array:
' -18 -5 0 7 12 33 42 89
'
