修复ac_time的问题，添加first_achieved逻辑
修复ac_time的问题，添加first_achieved逻辑

Timeship/OnlineJudge-QDU,Timeship/OnlineJudge-QDU,Timeship/OnlineJudge-1,Timeship/OnlineJudge-1,uestcxl/OnlineJudge,Timeship/OnlineJudge-QDU,wangmingjob/OnlineJudge,hxsf/OnlineJudge,wwj718/OnlineJudge,hxsf/OnlineJudge,wwj718/OnlineJudge,wangmingjob/OnlineJudge,Timeship/OnlineJudge-1,uestcxl/OnlineJudge,wangmingjob/OnlineJudge,uestcxl/OnlineJudge,hxsf/OnlineJudge,hxsf/OnlineJudge,wwj718/OnlineJudge,Timeship/OnlineJudge-QDU,Timeship/OnlineJudge-1,wangmingjob/OnlineJudge