Greatest common divisor: Difference between revisions

==={{header|Gambas}}===

====Iterative solution====

<syntaxhighlight lang="vbnet">Public Sub Main()

Dim a As Long = 111111111111111

Dim b As Long = 11111

Print "\nGCD("; a; ", "; b; ") = "; gcd(a, b)

Print "\nGCD("; a; ", 111) = "; gcd(a, 111)

End

Function gcd(x As Long, y As Long) As Long

Dim t As Long

While y

t = y

y = x Mod y

x = t

Wend

Return x

End Function</syntaxhighlight>

{{out}}

<pre>GCD(111111111111111, 11111) = 11111

GCD(111111111111111, 111) = 111</pre>

====Recursive solution====

<syntaxhighlight lang="vbnet">Function gcdp(a As Long, b As Long) As Long

If b = 0 Then Return a

Return gcdp(b, a Mod b)

End Function

Function gcd(a As Long, b As Long) As Long

Return gcdp(Abs(a), Abs(b))

End Function</syntaxhighlight>

This is a nearly-trivial 6-line function, so we've dressed it up a bit to show how easily FutureBASIC builds a full, interactive application. In FB, when you complete your code and hit RUN, the built app can open in as little as 3 seconds.

[[New_app_in_finder.png ]]

[[New_app_in_finder.png]]

[[Running app.png]]

begin enum 1 // Object tags

_fldA

_ansA

_fldB

_ansB

_rand

end enum

void local fn BuildMacInterface //15-line GUI

window 1, @"Greatest Common Divisor", ( 0, 0, 380, 130 ), NSWindowStyleMaskTitled + NSWindowStyleMaskClosable

textfield _fldA,,, ( 20, 89, 156, 21 )

ControlSetAlignment( _fldA, NSTextAlignmentRight )

ControlSetFormat( _fldA, @"0123456789", Yes, 18, 0 )

textfield _fldB,,, ( 20, 57, 156, 24 )

ControlSetAlignment( _fldB, NSTextAlignmentRight )

ControlSetFormat( _fldB, @"0123456789", Yes, 18, 0 )

textlabel _ansA, @"= ", ( 182, 91, 185, 16 )

textlabel _ansB, @"= ", ( 182, 62, 185, 16 )

button _rand,,,@"Random demo", ( 129, 13, 122, 32 )

menu 1,,, @"File" : menu 1,0,, @"Close", @"w" : MenuItemSetAction(1,0,@"performClose:")

editmenu 2

WindowMakeFirstResponder( 1, _fldA )

end fn

local fn GCD( a as long, b as long ) as long //the requested function

while b

long c = a mod b

a = b : b = c

wend

end fn = a

void local fn DoDialog( ev as Long, tag as long ) //This makes it interactive

long a, b, c

select ev

case _textFieldDidchange //Find GCD of edit fields' contents

a = fn ControlIntegerValue( _fldA )

b = fn ControlIntegerValue( _fldB )

if a + b == 0 then textlabel _ansA, @"=" : textlabel _ansB, @"=" : exit fn

c = fn GCD( a, b )

textlabel _ansA, fn stringwithformat(@"= %ld x %ld", c, a / c )

textlabel _ansB, fn stringwithformat(@"= %ld x %ld", c, b / c )

case _btnclick //Fill edit fields with random content, then process

select tag

case _rand

c = rnd(65536)

textfield _fldA,,str( c * rnd(65536) )

textfield _fldB,,str( c * rnd(65536) )

fn DoDialog( _textFieldDidchange, 0 )

end select

case _windowWillClose : end

end select

end fn

fn BuildMacInterface

on dialog fn doDialog

handleevents

<pre>

[[GCD of 814997010 and 4644003.png]] [[GCD of 1234567890 and 9876543210.png]] [[GCD of 51015 and 15051.png]] [[GCD of 1881 and 8118.png]] [[GCD of 42426466 and 2445968527.png ]] [[GCD of 123 and empty field.png]]

</pre>