L/SH/ScotRug Code Golf

golf.rb

g=Golf=Hash
def g.method_missing s, a
  k=[]
  case s.to_s[-1]
  when ?1
    a.reduce :*
  when ?2
    a.split.sort_by{|i| i[1] }*' '
  when ?3
    h1 1..a
  when ?4
    a.map { |i| i.
      sub(/(man.*)/,'hat(\1)').
      sub(/(dog.*)\)/,'\1(bone))').
      sub 'cat','dead'
    }
  when ?5
    a.size.times { |i| k += a.each_cons(i+1).to_a }
    k
  when ?6
    f="fizz"
    b="buzz"
    (1..a).map { |s|  s%3 > 0 ? s%5 > 0 ? s : b  : s%15>0 ? f : f+b }
  when ?7
    *r=0
    l,x=a
    m=l
    a.map {|a|
     x ? x=$_ : (m+=1) == a ? r[-1]=[l,a]*'-' : r<<l=m=a
    }
    r
  when ?8
    *i=0,1
    a.times { i << i[-1]+i[-2] }
    i[1..-2]
  when ?9
    b = open(a).map {|e| e.chomp.split ', '}
    g = z b
    while (c,d = g.minmax_by {|e,s| s.size})[0][1].size*2 < b.size
      b.select {|e,| e==c[0]}.map &:shift
      b -= [k]
      g = z b
    end
    d[0]
  when ?z
    a.group_by {|e,| e}
  end
end

601

x*2 < y

is shorter than

x < y/2.0

Under 600! (590)

In hole9 we can use minmax by instead of max_by then min_by.

586

We can use

[1,2,3]*' '

instead of

[1,2,3].join ' '

582

• hole2: don't need parentheses around ranges
• hole3:

a.times.size {}

is more efficient than

(1..a.size).map {}

579!

Hole 9: we can do the double association of minmax_by on a single line

576

• Hole 6: testing for

x>0

is more efficient than

x==0

566

• Hole 9:

array -= [[]]

is more efficient than

array.reject! &:empty?

Hole 6 if used x<1 instead of ==0 would not have had to rearrange order.

@morganp Heh, good spot. D'oh.

549

Seriously, make this end.

A step to far, but I guess all is fair in golf.

Added hole7 from @andrewmcdonough's repo in and back up to 617.

• My favourite bits are:

l,*x=a;
m=l

and

r<<l=m=a

• Also refactored method missing to check the last char instead of using a regex. Nicely obfuscates it since you have to use ?1 instead of /1/

615

• Lose the brackets in final sub method on hole 4

614

• Hole7: We can use

$_ #The last input line of string by gets or readline.

instead of nil since we aren't using gets/readline.

613

• Pull multiple <variable>=[] into a single k=[] at top of method.

I updated my rake file to this

RSpec::Core::RakeTask.new(:spec) do |spec|
  spec.rspec_opts = ["--fail-fast"]
  spec.pattern = 'spec/**/*_spec.rb'
end

So will only show first fail, faster to work through the first build. Relies on RSpec 2.1 though.

612

• Hole7: Since we are just setting x to anything, we don't need the *. - with thanks to @jonmountjoy

606

• Fun with parallel assignments

*e=0          #=> e = [0]
*e=0,1        #=> e = [0,1]
e, = [1,2,3]  #=> e = 1

602 is about as good as it gets for this route I think