Imports System
Public Class [MyClass]
Public Shared Sub getDistinct4Elements(ByVal arr As Integer(), ByVal sum As Integer)
Array.Sort(arr)
Dim size As Integer = arr.Length
For i As Integer = 0 To size - 4
For j As Integer = i + 1 To size - 3
Dim k As Integer = sum - (arr(i) + arr(j))
Dim fromstart As Integer = j + 1
Dim fromend As Integer = size - 1
While fromstart < fromend
If arr(fromstart) + arr(fromend) < k Then
fromstart += 1
ElseIf arr(fromstart) + arr(fromend) > k Then
fromend -= 1
Else
Console.Write(arr(i) & ", " & arr(j) & ", ")
Console.WriteLine(arr(fromstart) & ", " & arr(fromend))
fromstart += 1
fromend -= 1
End If
End While
Next
Next
End Sub
Public Shared Sub Main(ByVal args As String())
Dim arr As Integer() = New Integer() {4, 8, 1, 5, 9, 0, 3, 7}
Dim sum As Integer = 18
getDistinct4Elements(arr, sum)
End Sub
End Class
' run:
'
' 0, 1, 8, 9
' 0, 3, 7, 8
' 0, 4, 5, 9
' 1, 3, 5, 9
' 1, 4, 5, 8
'
