自動販賣機

假設有簡單的一自動販賣機販售三類商品，一類售價1元，一類售價2元，另一類售價3元。如果該販賣機只能投入1元及2元硬幣,只有一個投幣孔,可連續投入硬幣但自動販賣機會將總數超過3元的零錢自動退出。完成選擇後，將會賣出商品,若有餘額找回剩餘的零錢，隨後，機器又將返回初始的狀態Hi。

-Vending Machine assume a simple vending machine selling merchandise categories, one category at $ 1, the price of a Class 2 yuan, and the other the price of 3 yuan. If the vending machine can only put one yuan and 2 yuan coin, only one coin slot, continuous coin vending opportunities but will change the total number of more than 3 yuan automatic exit. Once selected, they will sell merchandise, if the balance of the remaining change back, then turn the machine returns to the initial state of Hi.