Public Sub KMPSearch(ByVal pattern As String, ByVal text As String) Dim M As Integer Dim N As Integer Dim lps() As Integer Dim j As Integer Dim i As Integer
' Inicialización
M = Len(pattern)
N = Len(text)
ReDim lps(M)
j = 0
' Calcular la tabla LPS (Longest Prefix Suffix)
ComputeLPSArray pattern, M, lps
' Búsqueda
i = 0
While i < N
If pattern(j) = text(i) Then
j = j + 1
i = i + 1
End If
If j = M Then
Debug.Print "Patrón encontrado en el índice " & (i - j)
j = lps(j - 1)
ElseIf i < N And pattern(j) <> text(i) Then
If j <> 0 Then
j = lps(j - 1)
Else
i = i + 1
End If
End If
Wend
End Sub
Private Sub ComputeLPSArray(ByVal pattern As String, ByVal M As Integer, ByRef lps() As Integer) Dim length As Integer Dim i As Integer
length = 0
i = 1
lps(0) = 0
While i < M
If pattern(i) = pattern(length) Then
length = length + 1
lps(i) = length
i = i + 1
Else
If length <> 0 Then
length = lps(length - 1)
Else
lps(i) = length
i = i + 1
End If
End If
Wend
End Sub