第19回オフラインリアルタイムどう書くの参考問題をRubyで解く

問題は
http://nabetani.sakura.ne.jp/hena/ord19sanwa/

def solve(q)
  nums = q.split(',').map(&:to_i)
  max_num = nums.max
  sums = []
  (1..max_num).each {|x|
    (x..max_num).each {|y|
      (y..max_num).each {|z|
        sum = [x,y,z,x*2,y*2,z*2,x*3,y*3,z*3]
        [x,y,z].combination(2){|a,b|
          sum << a + b
        }
        [x,x,y,y,z,z].combination(3){|a,b,c|
          sum << a + b + c
        }
        if ((nums & sum) == nums)
            sums << [x,y,z]
        end
      }
    }
  }
  case sums.size
  when 0
    'none'
  when 1
    sums[0].join(',')
  else
    'many'
  end
end

puts Time.now
DATA.readlines.each do |line|
  no,q,a = line.chop.split(/\s+/)
  ans = solve(q)
  print no + "\t" + ans
  puts ans == a ? ' o' : ' x'
end
puts Time.now

__END__
0   3,11,12,102,111,120 1,10,100
1   10,20,30,35,70  many
2   1,5,20,80   none
3   1,2,3,4,5,6,7,8,9,10,11,12,13,14    many
4   1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 1,4,5