[ENDED] Code Golf Contest #3

[JWinslow23]

This is the same deal as the other two contests.

NEXT: Here
PREVIOUS: Here

Challenge 3

Problem
Make a program that, given an integer of reasonable size, outputs the greatest prime factor of that integer, in binary, but with all 0s replaced with underscores (_) and all 1s replaced with minus signs (-).

Deadline
August 4, 2014, 1:00 AM EST

Sample input 1
15
Sample output 1
-_-
Sample input 2
7
Sample output 2
---
Sample input 3
115
Sample output 3
-_---

If any further clarification is necessary, contact me or willrandship, and we will explain the best we can.

Ranking

TI-83+ BASIC

Rank	User	Size	Date	Code
1	Runer112	75	8/3/2014 2:17:19 PM	Spoiler For Spoiler: For(A,Ans,2,~1 If not(fPart(Ans/A A->P End "B For(A,0,log(P)/log(2 sub("_-",iPart(2fPart(P/2/2^A))+1,1)+Ans End sub(Ans,1,A
2	JWinslow23	90	7/29/2014 11:43:19 AM	Spoiler For Spoiler: Ans->X X=1->A While X>1 2->A While fPart(X/A IS>(A,X End X/A->X End "_ If A " Ans->Str1 While A "_ If fPart(.5A "- Ans+Str1->Str1 int(.5A->A End Str1

Python2

Rank	User	Size	Date	Code
1	willrandship	147	7/29/2014 12:51:41 AM	Spoiler For Spoiler: def f(z):  for y in range(2,z+1):   if z%y:continue   return z if y==z else f(z/y) a="" for c in bin(f(input()))[2:]:a+='-'if c=='1'else'_' print a

Ruby

Rank	User	Size	Date	Code
1	Juju	115	7/29/2014 2:47:50 AM	Spoiler For Spoiler: a=gets.to_f;b=2;while a>1;(c=a/b)==c.to_i&&(a=c)||b+=1 end;p b.to_s(2).gsub('0','_').gsub('1','-')

Nspire Lua

Rank	User	Size	Date	Code
1	Jens_K	132	8/1/2014 6:59:33 AM	Spoiler For Spoiler: n=0+clipboard.getText()f=n repeat f=(f>2 and f-1 or n)until n%f<1 b=""repeat b=(f%2>0 and"-"or"_")..b;f=(f-f%2)/2 until f<1 print(b)

SysRPL

Rank	User	Size	Date	Code
1	3298	59.5	7/31/2014 5:18:48 PM	Spoiler For Spoiler: ::   FPTR2 ^NFactorSpc   DUPLENCOMP  NTHCOMPDROP   FPTR2 ^Z>#   NULL$SWAP BEGIN     DUP #2/ UNROT BINT1 #AND     #1= ITE CHR_- CHR_UndScore >T$   SWAP #0=UNTIL DROP ;

Perl

Rank	User	Size	Date	Code
1	willrandship	98	7/31/2014 2:15:31 PM	Spoiler For Spoiler: $z=<>;sub f{for(2..$z){$z/=$z%$_?next:$_;return$z>1?&f:$_;}}$_=sprintf"%b",f;s/1/-/g;s/0/_/g;print

Haskell

Rank	User	Size	Date	Code
1	3298	122	8/3/2014 6:16:11 PM	Spoiler For Spoiler: import Numeric g i=showIntAtBase 2c(f(i,2))"" f(1,j)=j f(i,j)=if mod i j==0then f(quot i j,j)else f(i,j+1) c 0='_' c 1='-'
2	bb010g	216	8/2/2014 7:11:01 PM	Spoiler For Spoiler: import Numeric;import Data.Char;main=fmap(\n->concatMap(\case{'0'->"_";_->"-"})$showIntAtBase 2intToDigit(last[x|x<-[1..n-1],n`mod`x==0,elem x[n|n<-[2..x],not$elem n[j*k|j<-[2..n-1],k<-[2..n-1]]]])"")readLn>>=putStr

CJam

Rank	User	Size	Date	Code
1	Runer112	16	8/3/2014 2:17:19 PM	Spoiler For Spoiler: q~mfZ=2b{"_-"=}%

Golfscript

Rank	User	Size	Date	Code
1	Runer112	33	8/3/2014 2:17:19 PM	Spoiler For Spoiler: ~.,2>-1%{].~%!=}/2base{"_-"=}%""+

Java

Rank	User	Size	Date	Code
1	Runer112	172	8/3/2014 2:17:19 PM	Spoiler For Spoiler: class C{public static void main(String[]a){long x=Long.decode(a[0]),i=x;while(i-->2)x=(x%i)==0?i:x;System.out.print(Long.toString(x,2).replace('0','_').replace('1','-'));}}
2	3298	185	8/3/2014 6:16:11 PM	Spoiler For Spoiler: class G{public static void main(String[]c){int n=Integer.parseInt(c[0]),i=2;while(i<n)if(n%i==0)n/=i;else++i;System.out.print(Integer.toString(n,2).replace('0','_').replace('1','-'));}}

TI-83+ z80

Rank	User	Size	Date	Code
1	Runer112	58	8/3/2014 2:17:19 PM	Spoiler For Spoiler: ;#SECTION "MAIN", CODE    org   userMem - 2    db   0BBh, 6Dh Start:    B_CALL   _RclAns    B_CALL   _ConvOP1    ld   h, d    ld   l, e TrialDivideLoop:    push   de    push   hl    B_CALL   _DivHLByDE    ld   a, h    or   l    pop   hl    pop   de    jq   nz, NotFactor    ld   h, d    ld   l, e NotFactor:    dec   de    ld   a, e    dec   a    or   d    jq   nz, TrialDivideLoop    ld   b, h    ld   c, l    ld   hl, OP1 + 15    ld   (hl), d BitLoop:    dec   hl    srl   b    rr   c    ld   (hl), '_'    jq   nc, BitUnset    ld   (hl), '-'    ld   d, h    ld   e, l BitUnset:    jq   nz, BitLoop    ex   de, hl    B_CALL   _PutS    B_CALL   _NewLine    ret

XTend

Rank	User	Size	Date	Code
1	3298	179	8/3/2014 6:16:11 PM	Spoiler For Spoiler: class G{def static void main(String[]c){var n=Integer.parseInt(c.get(0))var i=2while(i<n)if(n%i==0)n=n/i else i=i+1print(Integer.toString(n,2).replace('0','_').replace('1','-'))}}

Language Ranking

Rank	Lang	User	Size	Date
1	CJam	Runer112	16	8/3/2014 2:17:19 PM
2	Golfscript	Runer112	33	8/3/2014 2:17:19 PM
3	TI-83+ z80	Runer112	58	8/3/2014 2:17:19 PM
4	SysRPL	3298	59.5 (don't ask me why; I'm going off of what he said)	7/31/2014 5:18:48 PM
5	TI-83+ BASIC	Runer112	75	8/3/2014 2:17:19 PM
6	Ruby	Juju	98	7/30/2014 12:01:58 AM
7	Perl	willrandship	98	7/31/2014 2:15:31 PM
8	Haskell	3298	122	8/3/2014 6:16:11 PM
9	Nspire Lua	Jens_K	132	8/1/2014 6:59:33 AM
10	Python2	willrandship	147	7/29/2014 12:51:41 AM
11	Java	Runer112	172	8/3/2014 2:17:19 PM
12	XTend	3298	179	8/3/2014 6:16:11 PM

[Juju]

Ooh, interesting challenge here.

[willrandship]

By the way, if your language does not support underscores (ONLY if it does not) you may use a decimal [.] symbol instead.

[Runer112]

By the way, if your language does not support underscores (ONLY if it does not) you may use a decimal [.] symbol instead.

For the record, 83+ BASIC does support underscores (see this post). For consistent scoring of such entries, I'd suggest that all 83+ BASIC entries should be scored as if they used underscores (two byte tokens) rather than periods.

[willrandship]

Now everything's more complicated :\ stupid 2-byte tokens.

[JWinslow23]

Now everything's more complicated :\ stupid 2-byte tokens.

It's not complicated at all. I did it in 122 bytes. The prime factorization code was no problem. Neither was the binary conversion. It assumes anything 1 and under are valid.

EDIT: I totally changed my greatest prime factor algorithm so lists are not used, and I have 90 bytes! Update tomorrow.

[DJ Omnimaga]

Interesting challenge. I feel bad for Casio PRIZM ASM/C participants, though (good luck making an add-in under 29 KB large)

[Juju]

I changed my algorithm as well, only basic operations are used, so I got it down to 98 bytes

[calc84maniac]

So, I have a couple of questions.

Can we assume the input is at least 2? Otherwise, largest prime factor doesn't actually exist.
Also, can my output have a trailing space? That makes things easier in TI-BASIC because of silly string limitations.

If yes to both of these, then I have a 67-byte TI-BASIC solution.

[Princetonlion.tibd]

I feel like using 68k BASIC would be cheating, it has binary mode
I'm going to at least try, not sure if I'll manage to PM it though

[JWinslow23]

So, I have a couple of questions.

Can we assume the input is at least 2? Otherwise, largest prime factor doesn't actually exist.
Also, can my output have a trailing space? That makes things easier in TI-BASIC because of silly string limitations.

If yes to both of these, then I have a 67-byte TI-BASIC solution.

I actually don't know the rules on valid input. My 90 byte solution assumes input is any integer. Ask willrandship for confirmation, I don't know.

[Runer112]

So, I have a couple of questions.

Can we assume the input is at least 2? Otherwise, largest prime factor doesn't actually exist.
Also, can my output have a trailing space? That makes things easier in TI-BASIC because of silly string limitations.

If yes to both of these, then I have a 67-byte TI-BASIC solution.

Assuming that the input is at least 2 and an integer is fine, since any other numbers do not have a greatest prime factor. But I'd be of the opinion that a trailing space is not okay, especially in the case of TI-BASIC, in which the trailing space would become obvious when doing something like recalling or otherwise operating on Ans.

[3298]

Any entries below 60 bytes yet? I just submitted a 59.5-byte solution in SysRPL. (SysRPL runs on the HP calculators featuring a Saturn processor, which is a 4-bit one. That explains why half bytes are possible as a size there.)
My code calls some OS code to get a sorted list of prime factors (6 bytes, because that call is a flashpointer), and then takes the last element of that list (2 commands for 2.5 bytes each). Thus the assumptions are the same as the OS code's, which should be any integer >=1. (I don't know if 0 is fine as well, but I don't feel like risking a calculator crash to find out.)

[Princetonlion.tibd]

Mine is 100 something bytes, and it doesn't work yet. As you can tell, I still haven't learned to optimize 68k BASIC

[willrandship]

Yes, assuming >=2 is totally fine. IMO, code golf should be about handling the meat of the question, not about handling all the wacky edge cases. If ignoring edge cases makes a smaller solution, that's what I want to see.