Skip to content

Instantly share code, notes, and snippets.

@xacrimon

xacrimon/factor.bf

Created August 28, 2024 04:38
Show Gist options
  • Save xacrimon/cda4359ffdd65192e474e01b6e1eaef9 to your computer and use it in GitHub Desktop.
Save xacrimon/cda4359ffdd65192e474e01b6e1eaef9 to your computer and use it in GitHub Desktop.
Download ZIP
Raw
factor.bf
* factor an arbitrarily large positive integer
*
* Copyright (C) 1999 by Brian Raiter
* under the GNU General Public License
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>-
*
* read in the number
*
<<<<<<<<<+
[-[>>>>>>>>>>][-]<<<<<<<<<<[[->>>>>>>>>>+<<<<<<<<<<]<<<<<<<<<<]
>>>>>>>>>>,----------]
>>>>>>>>>>[------------------------------------->>>>>>>>>->]
<[+>[>>>>>>>>>+>]<-<<<<<<<<<<]-
*
* display the number and initialize the loop variable to two
*
[>++++++++++++++++++++++++++++++++++++++++++++++++.
------------------------------------------------<<<<<<<<<<<]
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
--------------------------.[-]
>>>>>>>>>>>>++<<<<+
*
* the main loop
*
[ [-]>>
*
* make copies of the number and the loop variable
*
[>>>>[-]>[-]>[-]>[-]
>[-]>[-]
<<<<<<<[->>>+>+<<<<]>>>>>>>>]
<<<<<<<<<<[>>>>>>[-<<<<+>>>>]<<<<<<<<<<<<<<<<]>>>>>>>>>>
[>[->>>+>>+<<<<<]>>>>>>>>>]
<<<<<<<<<<[>>>>>>[-<<<<<+>>>>>]<<<<<<<<<<<<<<<<]>>>>>>>>>>
*
* divide the number by the loop variable
*
[>>>[-]>>>[-]>[-]>>>] initialize
<<<<<<<<<<[<<<<<<<<<<]
>>>>>>>>>[-]>>>>>>>+<<<<<<<<[+]+
[ ->> double divisor until above dividend
[>>>>>>[->++<]>>>>]<<<<<<<<<<
[>>>>>>>>[-]>[-]
<<<<[->>>++<<<]<<<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>>[->+<[->+<[->+<[->+<[->+<[->+<[->+<[->+<[->+<
[->--------->>>>>>>>>+<<<<<<<<<<[->+<]]]]]]]]]]]>>]
<<<<<<<<<<[>>>>>>>>>[-<+<<<+>>>>]<<<<<<<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>[-<+>[-<+>[-<+>[-<+>[-<+>[-<+>[-<+>[-<+>[-<+>
[-<--------->>>>>>>>>>>+<<<<<<<<<<[-<+>]]]]]]]]]]]>>>]
<<<<<<<<<<
[>>>>[->>>+>>+<<<<<]<<<<<<<<<<<<<<]
>>>>>>>>>>[>>>>>>>[-<<<+>>>]>>>]<<<<<<<<<<
[>>>>>>>>[->-<]>
[<<<<<<<<<[<[-]>>>>>>>>>>[-<<<<<<<<<<+>>>>>>>>>>]<<<<<<<<<<<<<<<<<<<]
>>>>>>>>>>>>>>>>>>>]
<<<<<<<<<<<<<<<<<<<]
>>>>>>>>>[+[+[+[+[+[+[+[+[+[+[[-]<+>]]]]]]]]]]]<
]
>>>>>>>>
[ subtract divisor from dividend
<<<<<<
[>>>>>>>>[-]>[-]<<<<<[->>>+>+<<<<]>>>>>>]<<<<<<<<<<
[>>>>>>>>[-<<<<+>>>>]<<<[->>>+>+<<<<]<<<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>>>[-<<<<+>>>>]>]<<<<<<<<<<
[>>>>>>>>[-<->]<<<<<<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>[->+<[->+<[->+<[->+<[->+<[->+<[->+<[->+<[->+<[->+<
[++++++++++[+>-<]>>>>>>>>>>-<<<<<<<<<<]]]]]]]]]]]>>>]
>>>>>>>+
[ if difference is nonnegative then
[-]<<<<<<<<<<<<<<<<< replace dividend and increment quotient
[>>>>[-]>>>>[-<<<<+>>>>]<<[->>+<<]<<<<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>>[->+<<<+>>]>>]<<<<<<<<<<
[>>>[->>>>>>+<<<<<<]<<<<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>>>[-<<<<<<+>>>>>>[-<<<<<<+>>>>>>
[-<<<<<<+>>>>>>[-<<<<<<+>>>>>>
[-<<<<<<+>>>>>>[-<<<<<<+>>>>>>
[-<<<<<<+>>>>>>[-<<<<<<+>>>>>>
[-<<<<<<+>>>>>>[-<<<<<<--------->>>>>>>>>>>>>>>>+<<<<<<<<<<
[-<<<<<<+>>>>>>]]]]]]]]]]]>]
>>>>>>>
] halve divisor and loop until zero
<<<<<<<<<<<<<<<<<[<<<<<<<<<<]>>>>>>>>>>
[>>>>>>>>[-]<<[->+<]<[->>>+<<<]>>>>>]<<<<<<<<<<
[+>>>>>>>[-<<<<<<<+>>>>>>>[-<<<<<<<->>>>>>+>
[-<<<<<<<+>>>>>>>[-<<<<<<<->>>>>>+>
[-<<<<<<<+>>>>>>>[-<<<<<<<->>>>>>+>
[-<<<<<<<+>>>>>>>[-<<<<<<<->>>>>>+>
[-<<<<<<<+>>>>>>>]]]]]]]]]<<<<<<<
[->>>>>>>+<<<<<<<]-<<<<<<<<<<]
>>>>>>>
[-<<<<<<<<<<<+>>>>>>>>>>>]
>>>[>>>>>>>[-<<<<<<<<<<<+++++>>>>>>>>>>>]>>>]<<<<<<<<<<
[+>>>>>>>>[-<<<<<<<<+>>>>>>>>[-<<<<<<<<->>>>>+>>>
[-<<<<<<<<+>>>>>>>>[-<<<<<<<<->>>>>+>>>
[-<<<<<<<<+>>>>>>>>[-<<<<<<<<->>>>>+>>>
[-<<<<<<<<+>>>>>>>>[-<<<<<<<<->>>>>+>>>
[-<<<<<<<<+>>>>>>>>]]]]]]]]]<<<<<<<<
[->>>>>>>>+<<<<<<<<]-<<<<<<<<<<]
>>>>>>>>[-<<<<<<<<<<<<<+>>>>>>>>>>>>>]>>
[>>>>>>>>[-<<<<<<<<<<<<<+++++>>>>>>>>>>>>>]>>]<<<<<<<<<<
[<<<<<<<<<<]>>>>>>>>>>
>>>>>>
]
<<<<<<
*
* make copies of the loop variable and the quotient
*
[>>>[->>>>+>+<<<<<]>>>>>>>]
<<<<<<<<<<
[>>>>>>>[-<<<<+>>>>]<<<<<[->>>>>+>>+<<<<<<<]<<<<<<<<<<<<]
>>>>>>>>>>[>>>>>>>[-<<<<<+>>>>>]>>>]<<<<<<<<<<
*
* break out of the loop if the quotient is larger than the loop variable
*
[>>>>>>>>>[-<->]<
[<<<<<<<<
[<<[-]>>>>>>>>>>[-<<<<<<<<<<+>>>>>>>>>>]<<<<<<<<<<<<<<<<<<]
>>>>>>>>>>>>>>>>>>]<<<<<<<<<<<<<<<<<<]
>>>>>>>>[>-<[+[+[+[+[+[+[+[+[+[[-]>+<]]]]]]]]]]]>+
[ [-]
*
* partially increment the loop variable
*
<[-]+>>>>+>>>>>>>>[>>>>>>>>>>]<<<<<<<<<<
*
* examine the remainder for nonzero digits
*
[<<<<<<[<<<<[<<<<<<<<<<]>>>>+<<<<<<<<<<]<<<<]
>>>>>>>>>>>>>>>>>>>>[>>>>>>>>>>]<<<<<<<<<<[<<<<<<<<<<]
>>>>-
[ [+]
*
* decrement the loop variable and replace the number with the quotient
*
>>>>>>>>-<<[>[-]>>[-<<+>>]>>>>>>>]<<<<<<<<<<
*
* display the loop variable
*
[+>>[>>>>>>>>+>>]<<-<<<<<<<<<<]-
[>>++++++++++++++++++++++++++++++++++++++++++++++++.
------------------------------------------------<<<<<<<<<<<<]
++++++++++++++++++++++++++++++++.[-]>>>>
]
*
* normalize the loop variable
*
>>>>>>
[>>[->>>>>+<<<<<[->>>>>+<<<<<
[->>>>>+<<<<<[->>>>>+<<<<<
[->>>>>+<<<<<[->>>>>+<<<<<
[->>>>>+<<<<<[->>>>>+<<<<<
[->>>>>+<<<<<[->>>>>--------->>>>>+<<<<<<<<<<
[->>>>>+<<<<<]]]]]]]]]]]>>>>>>>>]
<<<<<<<<<<[>>>>>>>[-<<<<<+>>>>>]<<<<<<<<<<<<<<<<<]
>>>>>>>>>
]<
]>>
*
* display the number and end
*
[>>>>>>>>>>]<<<<<<<<<<[+>[>>>>>>>>>+>]<-<<<<<<<<<<]-
[>++++++++++++++++++++++++++++++++++++++++++++++++.<<<<<<<<<<<]
++++++++++.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment