10つくったー (https://shindanmaker.com/217387) ソルバ

ju_solver.rb

#!/usr/bin/env ruby
# ./ju_solver.rb 13 9 -3 73

ARGV.map(&:to_i).then { |ord|
  %i[+ - * /].repeated_combination(ord.size - 1).flat_map { |orr|
    (ord + orr).permutation((ord + orr).size).map { |formula|
      begin
        formula if formula.each.with_object([]) { |v, obj|
          if v.is_a? Symbol
            fail if obj.size < 2 || v == :/ && obj[-1].zero?
            obj[-2, 2] = obj[-2].send(v, obj[-1])
          else
            obj << v.to_r
          end
        }.first == 10
      rescue
      end
    }
  }
}.compact.each do |formula|
  puts formula.each.with_object([]) { |v, obj|
    if v.is_a? Symbol
      obj[-2, 2] = "(#{obj[-2, 2].join(" #{v} ")})"
    else
      obj << v
    end
  }[0]
end