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Ed H


Member


Joined: 30 Nov 2007
Posts: 138

Posted: 03 Jun 2008 07:02:44 pm    Post subject:

Edit: Okay, since some people didn't quite understand the challenge the first time, I reworded it.

Write a program that stores 54 binary bits in a 9-byte real number, and another program that retrieves the stored bits from the 9-byte real number. You should be able to input 54 binary bits into the first program, take the output from that program and input it into the second program, and get your original input back. You can use whatever input or output you want for either program; if your storage program outputs to Ans, and your retrieval program inputs from A, that's fine.

Aim for the smallest combined codesize (That is, codesize minus the length of the titles). So far the smallest anyone has got it is 151.


Last edited by Guest on 11 Jun 2008 01:47:06 pm; edited 1 time in total
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luby
I want to go back to Philmont!!


Calc Guru


Joined: 23 Apr 2006
Posts: 1477

Posted: 03 Jun 2008 10:09:18 pm    Post subject:

Your wording is a bit vauge. Are we to write a program that discerns whether to use a string or a list for input, or what??



sum(L12^seq(I,I,dim(L1)-1,0,‾1

int(round(2fPart(N2^seq(I,I,‾int(log(N)/log(2))-1,‾1

(source)http://weregoose.unitedti.org/routines.html
the first does what you specified for a list and the second returns a list of binary digits of number N


Last edited by Guest on 02 Aug 2010 01:56:55 am; edited 1 time in total
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Weregoose
Authentic INTJ


Super Elite (Last Title)


Joined: 25 Nov 2004
Posts: 3976

Posted: 03 Jun 2008 10:23:07 pm    Post subject:

Guh, I need to take that site down during challenges. :P

I also need to work on the updated version...


Last edited by Guest on 03 Jun 2008 10:23:18 pm; edited 1 time in total
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Ed H


Member


Joined: 30 Nov 2007
Posts: 138

Posted: 04 Jun 2008 10:15:26 am    Post subject:

luby wrote:
Your wording is a bit vauge. Are we to write a program that discerns whether to use a string or a list for input, or what??



sum(L12^seq(I,I,dim(L1)-1,0,‾1

int(round(2fPart(N2^seq(I,I,‾int(log(N)/log(2))-1,‾1

(source)http://weregoose.unitedti.org/routines.html
the first does what you specified for a list and the second returns a list of binary digits of number N
[post="124217"]<{POST_SNAPBACK}>[/post]

Choose whatever input or output you like. By the way, it's not that easy Wink . You need to store 54 bits. Store randInt(0,1,54 to L1, perform your first routine on it to A. Then perform your second routine on A and store the list to L2, and compare the lists.


Last edited by Guest on 02 Aug 2010 01:56:35 am; edited 1 time in total
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DarkerLine
ceci n'est pas une |


Super Elite (Last Title)


Joined: 04 Nov 2003
Posts: 8328

Posted: 04 Jun 2008 11:13:15 am    Post subject:

To clarify the wording of the challenge as I see it: the code isn't meant to convert the binary list to a real number. The idea is to somehow pack those 54 bits in the structure of a real number.
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Ed H


Member


Joined: 30 Nov 2007
Posts: 138

Posted: 05 Jun 2008 04:04:12 pm    Post subject:

Here's a solution. 151 bytes total.
68 bytes for storage, from a list in Ans to a real in Ans:
Quote:
:(1-2Ans(1))10^(sum(seq(2^(X-2)Ans(X),X,2,8)-6))(E13+sum(seq(2^(X-9)Ans(X),X,9,54

83 bytes for retrieval, from a real number in the variable A to a list in Ans:
Quote:
:29+int(log(abs(A
:augment({A<0},int(2fPart(Ans.5^seq(X,X,1,7→A
:-E13+abs(A10^(13-int(log(abs(A
:augment(∟A,int(2fPart(seq(fPart(Ans10^(-X))5^X,X,1,46

The code for converting a decimal to binary is loosely based off of one of Harrierfalcon's routines. Thanks =P.


Last edited by Guest on 05 Jun 2008 05:13:49 pm; edited 1 time in total
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