RE: [FWP] Brief Coding Methods

[Alistair.McGlinchy@marks-and-spencer.com]

Hi,

You may recall a few weeks ago I promised to summarise the results 
of the brief coding problem I put forward.  Well its better late than
never...

For those who have forgotten, the question was to solve the following
with the smallest number of characters. 

> The weekly circular contained a little puzzle. Find a 4 digit number ABCD
> and a five digit number EFGHI such that:
> 	 ABCD / EFGHI = 1 / 66 
> such that numbers 1 through 9 are all represented as digits in ABCD and
> EFGHI. 
> 
 
Amazingly enough the best solution so far takes only 44 chars to get
the value for ABCD, or 63 chars if you require the full formatted output.

[Note: In keeping with the netiquette rules of this list I have not named
names. 
My apologies to those who contributed and wanted their name up in pixels,
but 
I'd better keep to the rules. Contributors, please post your comments!]


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#Sol1 This was my original 74 char solution I had in mind when I 
#     posted the question, since then there have been many improvements.
#
for(;123456789-join("",sort split//,++$a.($b=$a*66));){};print"$a/$b=1/66"

#Sol2 Another suggested derivation, but a bit too long at 78 chars
#
L:while(1){$a++;for(1..9){($a.($b=$a*66))=~/$_/||next 
L}print"$a/$b=1/66";last}

#Sol3 With a bit of maths and applying a more tidy 1while construction
#     the join/split method can be reduced to 69 chars
#
1while((join"",sort split//,++$a.($b=$a*66))%10821);print"$a/$b=1/66"

#Sol4 This was blown out of the water by the use of RE's and map
#     down to only 49 chars. Note, this only prints the ABCD part
#     of the solution, but can find multiple solutions (Eg 44)
#
map{$p=66*$_;($_.$p)!~/0|(.).*\1/&&print}1E3..1E4

#Sol5 With slight tinkering Sol4 can be reduced to 44 chars
#     or into a pretty printed result with only 63 chars
#
map{print if($_.66*$_)!~/0|(.).*\1/}1E3..1E4
for($a=1E3;(++$a.($b=66*$a))=~/0|(.).*\1/;){};print"$a/$b=1/66"
	
So that's where its at now. Anyone have any different ideas on how 
to improve this. 

Cheers,

Alistair
--------------------------------------------------------------------
Alistair McGlinchy,         alistair.mcglinchy@marks-and-spencer.com
Sizing and Performance, Central IT  ext. 5012, ph +44 0 171-268-5012
Marks and Spencer (Stockley Park)              fx +44 0 171-268-5721
1SW, 3 Longwalk Rd, Stockley Park, Uxbridge UB11 1AW, United Kingdom
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