From: William James <w_a_x_man@...>
Date: 2007-01-15T10:15:06+09:00
Subject: Re: Number Spiral (#109)

Simon Kr�ger wrote:
> Dear Ruby Quiz,
>
> this isn't really a solution to the quiz 109 because it violates
> some (if not all) of the rules. But as James noted there was a
> code golf problem very similar to this quiz and here is my
> solution to that.
> (see http://codegolf.com/oblongular-number-spirals for detailed
> description of the code golf problem)
>
> ----------------------------------------------------------------
> s,f=1,proc{|x,y|y<1?[]:[[*s...s+=x]]+f[y-1,x].reverse.transpose}
> puts f[w=gets(' ').to_i,gets.to_i].map{|i|['%3i']*w*' '%i}
> ----------------------------------------------------------------
>
> It draws a number spiral, starting with '1' in the upper left
> corner and the highest number in the middle, it also features
> spirals that are not quadratic.
>
> Yes, you will get some score at the codegolf site if you repost
> this solution there - but nowadays you will only get to Rank 9
> with this solution and of course you will start to feel ill and
> you won't be able to sleep for days and other nasty things might
> happen if you do so.
>
> If someone can derive an even shorter solution from this i would
> be very interested to see it (the best ruby solution today has 7
> bytes less)

A reduction:

["stuff"]+[[4,5,6],[:x,:y,:z]].reverse.transpose
    ==>["stuff", [:x, 4], [:y, 5], [:z, 6]]
["stuff"]+(a,b=[[4,5,6],[:x,:y,:z]];b.zip a)
    ==>["stuff", [:x, 4], [:y, 5], [:z, 6]]