Balanced ternary: Difference between revisions

=={{header|FreeBASIC}}==

{{trans|Liberty BASIC}}

<lang freebasic>

#define MAX(a, b) iif((a) > (b), (a), (b))

Dim Shared As Integer pow, signo

Dim Shared As String t

t = "-0+"

Function deci(cadena As String) As Integer

Dim As Integer i, deci1

Dim As String c1S

pow = 1

For i = Len(cadena) To 1 Step -1

c1S = Mid(cadena,i,1)

signo = Instr(t, c1S)-2

deci1 = deci1 + pow * signo

pow *= 3

Next i

Return deci1

End Function

Function ternary(n As Integer) As String

Dim As String ternario

Dim As Integer i, k

While Abs(n) > 3^k/2

k += 1

Wend

k -= 1

pow = 3^k

For i = k To 0 Step -1

signo = (n>0) - (n<0)

signo *= (Abs(n) > pow/2)

ternario += Mid(t,signo+2,1)

n -= signo*pow

pow /= 3

Next

If ternario = "" Then ternario = "0"

Return ternario

End Function

Function negate(cadena As String) As String

Dim As String negar = ""

For i As Integer = 1 To Len(cadena)

negar += Mid(t, 4-Instr(t, Mid(cadena,i,1)), 1)

Next i

Return negar

End Function

Function pad(cadenaA As String, n As Integer) As String

Dim As String relleno = cadenaA

While Len(relleno) < n

relleno = "0" + relleno

Wend

Return relleno

End Function

Function addTernary(cadenaA As String, cadenaB As String) As String

Dim As Integer l = max(Len(cadenaA), Len(cadenaB))

Dim As Integer i, x, y, z

cadenaA = pad(cadenaA, l)

cadenaB = pad(cadenaB, l)

Dim As String resultado = ""

Dim As Byte llevar = 0

For i = l To 1 Step -1

x = Instr(t, Mid(cadenaA,i,1))-2

y = Instr(t, Mid(cadenaB,i,1))-2

z = x + y + llevar

If Abs(z) < 2 Then

llevar = 0

Elseif z > 0 Then

llevar = 1: z -= 3

Elseif z < 0 Then

llevar = -1: z += 3

End If

resultado = Mid(t,z+2,1) + resultado

Next i

If llevar <> 0 Then resultado = Mid(t,llevar+2,1) + resultado

i = 0

While Mid(resultado,i+1,1) = "0"

i += 1

Wend

resultado = Mid(resultado,i+1)

If resultado = "" Then resultado = "0"

Return resultado

End Function

Function subTernary(cadenaA As String, cadenaB As String) As String

Return addTernary(cadenaA, negate(cadenaB))

End Function

Function multTernary(cadenaA As String, cadenaB As String) As String

Dim As String resultado = ""

Dim As String tS = "", cambio = ""

For i As Integer = Len(cadenaA) To 1 Step -1

Select Case Mid(cadenaA,i,1)

Case "+": tS = cadenaB

Case "0": tS = "0"

Case "-": tS = negate(cadenaB)

End Select

resultado = addTernary(resultado, tS + cambio)

cambio += "0"

Next i

Return resultado

End Function

Dim As String cadenaA = "+-0++0+"

Dim As Integer a = deci(cadenaA)

Print " a:", a, cadenaA

Dim As Integer b = -436

Dim As String cadenaB = ternary(b)

Print " b:", b, cadenaB

Dim As String cadenaC = "+-++-"

Dim As Integer c = deci(cadenaC)

Print " c:", c, cadenaC

'calcular en ternario

Dim As String resS = multTernary(cadenaA, subTernary(cadenaB, cadenaC))

Print "a*(b-c):", deci(resS), resS

Print !"\nComprobamos:"

Print "a*(b-c): ", a * (b - c)

Sleep

</lang>

{{out}}

<pre>

a: 523 +-0++0+

b: -436 -++-0--

c: 65 +-++-

a*(b-c): -262023 ----0+--0++0

Comprobamos:

a*(b-c): -262023

</pre>