Imports System
Imports System.Collections.Generic
Public Class Program
Public Shared Sub findPairs(ByVal arr As Integer(), ByVal diff As Integer)
Dim _set As ISet(Of Integer) = New HashSet(Of Integer)()
For Each i As Integer In arr
If _set.Contains(i - diff) Then
Console.WriteLine(i & ", " & (i - diff))
End If
If _set.Contains(i + diff) Then
Console.WriteLine((i + diff) & ", " & i)
End If
_set.Add(i)
Next
End Sub
Public Shared Sub Main(ByVal args As String())
Dim arr As Integer() = New Integer() {4, 1, 7, 5, 8, 6, 9, 10, 12, 11}
Dim diff As Integer = 3
findPairs(arr, diff)
End Sub
End Class
' run:
'
' 4, 1
' 7, 4
' 8, 5
' 9, 6
' 10, 7
' 12, 9
' 11, 8
'
