Code Golf: All +-*/ Combinations for 3 integers

Answer 1

Ruby

(reads from argument list and returns NaN if not divisible)

(would be only the last line if ruby had a permutation library)

class Array
  def perm(n = size)
    if size < n or n < 0
    elsif n == 0
      yield([])
    else
      self[1..-1].perm(n - 1) do |x|
        (0...n).each do |i|
          yield(x[0...i] + [first] + x[i..-1])
        end
      end
      self[1..-1].perm(n) do |x|
        yield(x)
      end
    end
  end
end

ARGV.perm(3){|a,b,c| "++//**--".split(//).perm(2){ |d,e| x=a+d+b+e+c;puts "#{x} = #{eval(x)}" rescue puts "#{x} = NaN"} }