golf.rb

class Golf
  class << self
    def hole1 a 
      a.reduce :*
    end

    def hole2 s 
      s.split.sort_by{|i| i[1] }.join ' '
    end

    def hole3 i 
      hole1 (1..i)
    end

    def hole4 a 
      a.map { |i| i.
        sub(/(man.*)/,'hat(\1)').
        sub(/(dog.*)\)/,'\1(bone))').
        sub('cat','dead')
      }
    end

    def hole5 a 
      r = []
      s = a.size
      (1..s).each { |x|
        (0..s-x).each { |y|
          r << a[y,x]
        }
      }
      r
    end

    def hole6 i 
      f="fizz"
      b="buzz"
      (1..i).map { |s| ( s%15 == 0 ? f+b : (s%3 == 0 ? f : (s%5 == 0 ? b : s) ) ) }
    end

    def hole8 i 
      a = [1,1]
      (1..i-2).each { |i| a << a[i-1] + a[i] }
      a
    end


    def z a
      a.group_by {|e| e[0]}
    end

    def hole9 f
      b = open(f).map {|e| e.chomp.split ', '}
      g = z b
      while (a = g.max_by {|e,s| s.size})[1].size < b.size/2.0
        r = g.min_by {|e,s| s.size}[0]
        b.select {|e| e[0]==r}.map &:shift
        b.reject! &:empty?
        g = z b
      end
      a[0]

    end
  end
end