>
¶ȼԭ
Ȳͬһ𣬻Ӵһʱ¶Ⱦͻﵽͬȳ̶ȡ ʱÿѧ˵ﵽƽ⡣
ٽһֱΪABCȳ̶Ȳͬ ABʹABCӴһʱACBCﵽƽ⡣ ʱʹABӴᷢAB֮䲻ȴݣԵ¶Ҳ仯 ˵ABڿʼӴʱʹƽ״̬ ɴ˻õһۣABCƽ״̬ABҲضƽ״̬ һлΪƽ嶼ͬ¶ȡ ¶ȼⶨ¶ȵݣ