choice = ['g','c','p']

my = process.argv[2]
enemy = (->
  choice[Math.floor(Math.random() * choice.length)]
)()

console.log "my: #{my}"
console.log "enemy: #{enemy}"

judge = (my,enemy) ->
  table = {g: "c" ,c: "p",p: "g"}
  if my in choice and enemy in choice
    switch enemy
      when table[my] then return "Win"
      when my then return "Draw"
      else
        return "Lose"
  else
    return "error"

console.log judge(my,enemy)