Solution for d2020 day 18

Dependencies

• [2] B527MN66 Solve day 1 for 2020

Change contents

• file addition: day18.rb (----------)
  [2.17]
  + input = (ARGV[1] && ARGV[1] != '-') ? File.open(ARGV[1], "r") : STDIN

  +

  + statements = []

  + input.each_line.each_with_index do |line,line_num|

  + vars = [{ var: 'b', var2: 'c' }]

  + ce = ''

  + line.each_char do |c|

  + if /[0-9]/ === c

  + ce += c

  + elsif ce.length > 0

  + var = vars.last

  + case ARGV[0]

  + when '1'

  + statements << "#{var[:var]} #{var[:op]}= #{ce}"

  + when '2'

  + statements << "#{var[:var2]} #{var[:o2]}= #{ce}"

  + var[:o2] = '+'

  + end

  + ce = ''

  + end

  + if /[\*\+]/ === c

  + case ARGV[0]

  + when '1'

  + vars.last[:op] = c

  + when '2'

  + var = vars.last

  + if '*' === c

  + statements << "#{var[:var]} #{var[:o1]}= #{var[:var2]}"

  + var[:o2] = nil

  + var[:o1] = '*'

  + else

  + end

  + end

  + elsif '(' === c

  + var = vars.last

  + vars << case ARGV[0]

  + when '1'

  + { var: var[:var].succ }

  + when '2'

  + s = var[:var2].succ

  + { var: s, var2: s.succ }

  + end

  + elsif ')' === c

  + var = vars.pop

  + next_var = vars.last

  + case ARGV[0]

  + when '1'

  + statements << "#{next_var[:var]} #{next_var[:op]}= #{var[:var]}"

  + when '2'

  + statements << "#{var[:var]} #{var[:o1]}= #{var[:var2]}"

  + statements << "#{next_var[:var2]} #{next_var[:o2]}= #{var[:var]}"

  + next_var[:o2] = '+'

  + end

  + end

  + end

  + if '2' === ARGV[0]

  + if ce.length > 0

  + statements << "#{vars[0][:var2]} #{vars[0][:o2]}= #{ce}"

  + end

  + statements << "#{vars[0][:var]} #{vars[0][:o1]}= #{vars[0][:var2]}"

  + end

  + statements << "a #{line_num > 0 ? '+' : ''}= b"

  + end

  + func = "-> do\n#{statements.map{|s| " #{s}" }.join("\n")}\n a\nend"

  + func = binding.eval func

  +

  + puts func.call

  +