c++第九章第四题

#ifndef SALES_H_  //.h
#define SALES_H_
namespace SALES {
   class Sales
   {
    private:
             enum { qu = 4 };
             double sales[qu];
             double average;
             double max;
             double min;
    public:
             inline Sales();  //这里必须要有inline！！！
             Sales(const double ar[], int n);
             void setsales();
             void showsales()const;
};
Sales::Sales()
 {
  for (int i = 0; i < qu; i++)
   sales[i] = 0;
  average = 0;
  max = 0;
  min = 0;
 }
}  //cpp
#endif
#include<iostream>
#include"81.h"
static double a, b, c;
SALES::Sales::Sales(const double ar[], int n)
{
 a = b = ar[0];
 c = 0.0;
 for (int i = 0; i < n; i++)
 {
  sales[i] = ar[i];
  c += sales[i];
  if (ar[i] > a)
   a = ar[i];
  if (ar[i < b])
   b = ar[i];
 }
 average = c / n;
 max = a;
 min = b;
 showsales();
}
void SALES::Sales::setsales()
{
 double br[qu];
 int n = 0;
 c = 0.0;
 std::cout << "\nenter the number: ";
 do
 {
  std::cin >> br[n];
  n++;
 } while (n<qu);
 for (int i = 0; i < n; i++)
 {
  sales[i] = br[i];
  c += sales[i];
  if (br[i] > a)
   a = br[i];
  if (br[i < b])
   b = br[i];
 }
 average = c / n;
 max = a;
 min = b;
}
void SALES::Sales::showsales() const
{
 std::cout << "\nthe average: " << average;
 std::cout << "\nthe max number: " << max;
 std::cout << "\nthe min number: " << min;
}         //cpp
#include<iostream>
#include"81.h"
int main()
{
 std::cout << "第九题第四题\n";
 double arr[4] = { 11,22,44,33 };
 SALES::Sales sales1(arr, 4);
 SALES::Sales sales2;
 sales2.setsales();
 sales2.showsales();
 return 0;
}