第10章第4题

#ifndef SALE_H_#define SALE_H_namespace SALE{ class sale { enum {Len = 4}; private: double sales[Len]; double avg; double max; double min; public: sale(); sale(const double* dt , int l = Len);//还有个函数其实是复制构造函数，属于后面11章内容，所以我就没写进去 ~sale(); void show()const; };}#endif

#include<iostream>#include"sale.h"namespace SALE{ sale::sale() { sales[Len] = (0,0,0,0); avg = 0; max = 0; min = 0; } sale::sale(const double* dt , int l) { double A = 0; max = *dt; min = *dt; for(int i = 0 ; i < l ; ++i) { *(sales+i) = *(dt+i); A += *(dt+i); if(max < *(dt+i)) max = *(dt+i); if(min > *(dt+i)) min = *(dt+i); } avg = A/l; } sale::~sale() { } void sale::show()const { for(int i = 0 ; i < Len ; ++i) std::cout<<"第"<<i+1<<"个数为:"<<*(sales+i)<<"\n"; std::cout<<"平均值:"<<avg<<"\n"; std::cout<<"最大值:"<<max<<"\n"; std::cout<<"最小值:"<<min<<"\n"; }}

#include<iostream>#include"sale.h"using namespace SALE;int main(){ double datas[4]; for(int i = 0 ; i < 4 ; ++i) { std::cout<<"请输入第"<<i+1<<"个数:"; std::cin>>*(datas+i); //别输错了。。。 } sale A(datas); A.show(); return 0;}