函数,C++~帮看一下吧~不是很明白
classItem_base{friendstd::istream&operator>>(std::istream&,Item_base&);friendstd::ostream&operator<<(std::ostream&,constItem_base&); *clone()const{returnnewItem_base(*this);} (conststd::string&book="",doublesales_price=0.0):isbn(book),price(sales_price){}std::stringbook()const{returnisbn;}//returnstotalsalespriceforaspecifiednumberofitems//derivedclasseswilloverrideandapplydifferentdiscountalgorithmsvirtualdoublenet_price(std::size_tn)const{returnn*price;}//nowork,butvirtualdestructorneeded//ifbasepointerthatpointstoaderivedobjectiseverdeletedvirtual~Item_base(){} ::stringisbn;//identifierfortheitem //normal,undiscountedprice};这里的clone()函数不太明白,Item_base(*this);没有匹配的构造函数呀?
答：公式应该没有问题,问题应该在表一,对表一按B列进行升序排序后就能得到正确结果.详情>>
答：找到对方的IP，输入IE地址里就行了！详情>>
