分析如图所示电路的功能，写出状态表或状态转换图，说明电路的类型？<br /> <img src="https://nimg.ppkao.com/2019-04/wangjue/2019041613111585529.jpg?sign=e93a263210aec89234eacebe422b2fa6&t=62d71fe9" />