????step3:?б??????>??????????????

????expect:1???????????????????1

????2???б???????????????????????????

????3?????????????????

????4???????=?????/??????????????

????step4:?б??????>?????????????????????

????expect:1?????????????

????2??????????????

????3??????????????(?????????+1)???????????????????+1

????4??β?????????????????

????step5:?б??????>???????????????????м????

????expect:1??????????????1???????????????

????2???????????????????????

????3?????????????????????

????4??β?????????????????

????5???б???????????????????????????

????6??????????????

????step6:?б??????>??????????????????β?

????expect:1??????????????1???????????????

????2???????????????????????

????3??????????????

????4??β?????????

????5???б???????????????????????????

????6??????????????????

????step7:????????????????????

????expect:1??????????????3??????????

????2?????????????????????????

????3??????????3??б??????/?????????