Data commit

Task/Vigen-re-cipher/FreeBASIC/vigen-re-cipher.basic

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+Function Filtrar(cadorigen As String) As String
+    Dim As String letra
+    Dim As String filtrado = ""
+    For i As Integer = 1 To Len(cadorigen)
+        letra = Ucase(Mid(cadorigen, i, 1))
+        If Instr("ABCDEFGHIJKLMNOPQRSTUVWXYZ", letra) Then filtrado += letra
+    Next i
+    Return filtrado
+End Function
+
+Function Encriptar(texto As String, llave As String) As String
+    texto = Filtrar(texto)
+    Dim As String mSS, kSS, letra, cifrado = ""
+    Dim As Integer m, k, c, j = 1
+    For i As Integer = 1 To Len(texto)
+        mSS = Mid(texto, i, 1)
+        m = Asc(mSS) - Asc("A")
+        kSS = Mid(llave, j, 1)
+        k = Asc(kSS) - Asc("A")
+        j = (j Mod Len(llave)) + 1
+        c = (m + k) Mod 26
+        letra = Chr(Asc("A") + c)
+        cifrado += letra
+    Next i
+    Return cifrado
+End Function
+
+Function DesEncriptar(texto As String, llave As String) As String
+    Dim As String mSS, kSS, letra, descifrado = ""
+    Dim As Integer m, k, c, j = 1
+    For i As Integer = 1 To Len(texto)
+        mSS = Mid(texto, i, 1)
+        m = Asc(mSS) - Asc("A")
+        kSS = Mid(llave, j, 1)
+        k = Asc(kSS) - Asc("A")
+        j = (j Mod Len(llave)) + 1
+        c = (m - k + 26) Mod 26
+        letra = Chr(Asc("A")+c)
+        descifrado += letra
+    Next i
+    Return descifrado
+End Function
+
+Dim Shared As String llave
+llave = Filtrar("vigenerecipher")
+
+Dim As String cadorigen = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!"
+Print cadorigen
+Print llave
+
+Dim As String cadcifrada = Encriptar(cadorigen, llave)
+Print "   Cifrado: "; cadcifrada
+Print "Descifrado: "; DesEncriptar(cadcifrada, llave)
+Sleep