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Calculations Needing Big Integers....
#8
(07-09-2023, 02:20 PM)SMcNeill Wrote:
Code: (Select All)
Screen _NewImage(1280, 720, 32)
Limit = 10000
Print "Fib"; Limit; "="
last2$ = "0"
last$ = "1"
time## = Timer
For i = 1 To Limit - 2
    result$ = StringAdd(last$, last2$)
    last2$ = last$
    last$ = result$
Next
Print result$
Print Using "###.### seconds to run."; Timer - time##

End

Function StringAdd$ (tempa$, tempb$)
    a$ = tempa$: b$ = tempb$ 'don't alter our original numbers
    Dim As _Unsigned _Integer64 a, b, c, carryover 'to hold our values

    'first fix the numbers to notmalize their lengths
    FixNumbers a$, b$
    'find the signs and strip them off
    If Left$(a$, 1) = "-" Then sa$ = "-": a$ = Mid$(a$, 2) Else sa$ = " "
    If Left$(b$, 1) = "-" Then sb$ = "-": b$ = Mid$(b$, 2) Else sb$ = " "
    'find the decimal position
    dp = InStr(a$, ".")
    If dp > 0 Then 'remove the decimal place from our numbers.  We can put it back later, in its proper position
        righta$ = Mid$(a$, dp + 1)
        rightb$ = Mid$(b$, dp + 1)
        a$ = Left$(a$, dp - 1) + righta$
        b$ = Left$(b$, dp - 1) + rightb$
    End If
    'our strings are now nothing but numbers with no signs and no decimals to deal with.  Let's start adding!
    'are we adding or really subtracting?

    If sa$ <> sb$ Then 'we're subtracting the two values if the signs aren't the same.
        Select Case a$
            Case Is < b$: s$ = sb$: Swap a$, b$ 'our sign is going to be determiined by b$
            Case Is = b$ 'if the two values are the same and are subtracting, our result is zero!
                StringAdd$ = "0" 'How easy was that?
                Exit Function
            Case Else: s$ = sa$ 'our sign is determined by a$
        End Select
        Do
            lb = Len(b$)
            a = Val(Right$(a$, 18)): a$ = Left$(a$, Len(a$) - 18)
            b = Val(Right$(b$, 18)): b$ = Left$(b$, Len(b$) - 18)
            If borrow Then b = b + 1~&& 'in case we had to borrow a digit for the last subtraction
            If a < b Then
                If lb < 18 Then a = a + 10 ^ lb Else a = a + 10 ^ 18
                borrow = -1
            Else
                borrow = 0
            End If
            c = a - b
            temp$ = _Trim$(Str$(c))
            answer$ = String$(18 - Len(temp$), "0") + temp$ + answer$
        Loop Until Len(a$) = 0
        'remove leading 0's
        Do Until Left$(answer$, 1) <> "0"
            answer$ = Mid$(answer$, 2)
        Loop
        'remember to add in the decimal place before finished
        dp = Len(righta$)
        If dp > 0 Then
            answer$ = Left$(answer$, Len(answer$) - dp) + "." + Right$(answer$, dp)
        End If
        StringAdd$ = s$ + answer$
        Exit Function
    End If

    Do
        a1$ = Right$(a$, 18)
        b1$ = Right$(b$, 18)
        a = Val(Right$(a$, 18)): a$ = Left$(a$, Len(a$) - 18)
        b = Val(Right$(b$, 18)): b$ = Left$(b$, Len(b$) - 18)
        c = a + b + carryover
        temp$ = _Trim$(Str$(c))
        If Len(temp$) > 18 Then 'see if we have an answer that is more than 18 digits
            temp$ = Right$(temp$, 18) 'keep 18 digits
            carryover = 1 'store one for carry over
        Else
            carryover = 0 'no carryover
        End If
        answer$ = String$(18 - Len(temp$), "0") + temp$ + answer$
    Loop Until Len(a$) = 0
    If carryover Then answer$ = "1" + answer$
    'remember to add in the decimal place before finished
    dp = Len(righta$)
    If dp > 0 Then
        answer$ = Left$(answer$, Len(answer$) - dp) + "." + Right$(answer$, dp)
    End If
    'remove leading 0's
    Do Until Left$(answer$, 1) <> "0"
        answer$ = Mid$(answer$, 2)
    Loop
    StringAdd$ = sa$ + answer$
End Function

Function StringSubtract$ (tempa$, tempb$)
    a$ = tempa$: b$ = tempb$
    FixNumbers a$, b$
    If Left$(b$, 1) = "-" Then b$ = Mid$(b$, 2) Else b$ = "-" + b$
    StringSubtract$ = StringAdd$(a$, b$)
End Function


Sub FixNumbers (a$, b$)
    'first remove scientific notation and spaces from both
    a$ = _Trim$(N2S$(a$)): b$ = _Trim$(N2S$(b$))
    'then find the decimal position for both and normalize the expressions
    d1 = InStr(a$, "."): d2 = InStr(b$, ".")
    If d1 <> 0 Then 'break down the left and right side of the decimal point for ease of processing  (this is a$)
        lefta$ = Left$(a$, d1 - 1)
        righta$ = Mid$(a$, d1)
    Else
        lefta$ = a$
    End If
    If d2 <> 0 Then 'break down the left and right side of the decimal point for ease of processing  (this is b$)
        leftb$ = Left$(b$, d2 - 1)
        rightb$ = Mid$(b$, d2)
    Else
        leftb$ = b$
    End If

    'normalize the right side of our expressions
    l1 = Len(righta$): l2 = Len(rightb$)
    If l1 < l2 Then
        addzero = l2 - l1
        If l1 = 0 Then righta$ = ".": addzero = addzero - 1
        righta$ = righta$ + String$(addzero, "0")
    ElseIf l1 > l2 Then
        addzero = l1 - l2
        'If l2 = 0 Then rightb$ = ".": addzero = addzero - 1
        rightb$ = rightb$ + String$(addzero, "0")
    End If



    'strip off any plus/minus signs from the two numbers.
    If Left$(lefta$, 1) = "-" Then signa$ = "-": lefta$ = Mid$(lefta$, 2)
    If Left$(leftb$, 1) = "-" Then signb$ = "-": leftb$ = Mid$(leftb$, 2)
    If Left$(lefta$, 1) = "+" Then signa$ = "": lefta$ = Mid$(lefta$, 2)
    If Left$(leftb$, 1) = "+" Then signb$ = "": leftb$ = Mid$(leftb$, 2)
    'normalize the left side of our expressions
    l1 = Len(lefta$): l2 = Len(leftb$)
    If l1 < l2 Then
        addzero = l2 - l1
        lefta$ = String$(addzero, "0") + lefta$
    ElseIf l1 > l2 Then
        addzero = l1 - l2
        leftb$ = String$(addzero, "0") + leftb$
    End If
    'and then put it all together
    a$ = signa$ + lefta$ + righta$
    b$ = signb$ + leftb$ + rightb$
End Sub





Function N2S$ (exp$) 'scientific Notation to String

    t$ = LTrim$(RTrim$(exp$))
    If Left$(t$, 1) = "-" Or Left$(t$, 1) = "N" Then sign$ = "-": t$ = Mid$(t$, 2)

    dp = InStr(t$, "D+"): dm = InStr(t$, "D-")
    ep = InStr(t$, "E+"): em = InStr(t$, "E-")
    check1 = Sgn(dp) + Sgn(dm) + Sgn(ep) + Sgn(em)
    If check1 < 1 Or check1 > 1 Then N2S = exp$: Exit Function 'If no scientic notation is found, or if we find more than 1 type, it's not SN!

    Select Case l 'l now tells us where the SN starts at.
        Case Is < dp: l = dp
        Case Is < dm: l = dm
        Case Is < ep: l = ep
        Case Is < em: l = em
    End Select

    l$ = Left$(t$, l - 1) 'The left of the SN
    r$ = Mid$(t$, l + 1): r&& = Val(r$) 'The right of the SN, turned into a workable long


    If InStr(l$, ".") Then 'Location of the decimal, if any
        If r&& > 0 Then
            r&& = r&& - Len(l$) + 2
        Else
            r&& = r&& + 1
        End If
        l$ = Left$(l$, 1) + Mid$(l$, 3)
    End If

    Select Case r&&
        Case 0 'what the heck? We solved it already?
            'l$ = l$
        Case Is < 0
            For i = 1 To -r&&
                l$ = "0" + l$
            Next
            l$ = "0." + l$
        Case Else
            For i = 1 To r&&
                l$ = l$ + "0"
            Next
    End Select

    N2S$ = sign$ + l$
End Function


Function DWD$ (exp$) 'Deal With Duplicates
    'To deal with duplicate operators in our code.
    'Such as --  becomes a +
    '++ becomes a +
    '+- becomes a -
    '-+ becomes a -
    t$ = exp$
    Do
        bad = 0
        Do
            l = InStr(t$, "++")
            If l Then t$ = Left$(t$, l - 1) + "+" + Mid$(t$, l + 2): bad = -1
        Loop Until l = 0
        Do
            l = InStr(t$, "+-")
            If l Then t$ = Left$(t$, l - 1) + "-" + Mid$(t$, l + 2): bad = -1
        Loop Until l = 0
        Do
            l = InStr(t$, "-+")
            If l Then t$ = Left$(t$, l - 1) + "-" + Mid$(t$, l + 2): bad = -1
        Loop Until l = 0
        Do
            l = InStr(t$, "--")
            If l Then t$ = Left$(t$, l - 1) + "+" + Mid$(t$, l + 2): bad = -1
        Loop Until l = 0
    Loop Until Not bad
    DWD$ = t$
End Function

Holy cow that's fast!
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Messages In This Thread
RE: Calculations Needing Big Integers.... - by TerryRitchie - 07-09-2023, 02:25 PM



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