Dim Shared As Long array(9), pivote

Function QuickPartition (array() As Long, izda As Long, dcha As Long, pivote As Long) As Long
    Dim As Long pivotValue = array(pivote)
    Swap array(pivote), array(dcha)
    Dim As Long indice = izda
    For i As Long = izda To dcha-1
        If array(i) < pivotValue Then
            Swap array(indice), array(i)
            indice += 1
        End If
    Next i
    Swap array(dcha), array(indice)
    Return indice
End Function

Function QuickSelect(array() As Long, izda As Long, dcha As Long, k As Long) As Long
    Do
        If izda = dcha Then Return array(izda) : End If
        pivote = izda
        pivote = QuickPartition(array(), izda, dcha, pivote)
        Select Case k
        Case pivote
            Return array(k)
        Case Is < pivote
            dcha = pivote - 1
        Case Is > pivote
            izda = pivote + 1
        End Select
    Loop
End Function

Dim As Long a = Lbound(array), b = Ubound(array)
Print "Array desordenado:  ";
For i As Long = a To b
    Read array(i)
    Print array(i);
Next i
Data 9, 8, 7, 6, 5, 0, 1, 2, 3, 4

Print !"\n\n   Array ordenado:  ";
For i As Long = a To b
    Print QuickSelect(array(), a, b, i);
Next i
Sleep