Sales_data.h
1 #ifndef SALES_DATA_H 2 #define SALES_DATA_H 3 4 #include "Version_test.h" 5 6 #include <string> 7 8 struct Sales_data { 9 std::string bookNo; 10 #ifdef IN_CLASS_INITS 11 unsigned units_sold = 0; 12 double revenue = 0.0; 13 #else 14 unsigned units_sold; 15 double revenue; 16 #endif 17 }; 18 #endif
- 定义了Slaes_data类
- 作者想让读者自己定义一遍Sales_item类，所以在此没有定义操作
Sales_data.cpp
1 #include <iostream> 2 #include <string> 3 #include "Sales_data.h" 4 5 int main() 6 { 7 Sales_data data1, data2; 8 9 // code to read into data1 and data2 10 double price = 0; // price per book, used to calculate total revenue 11 12 // read the first transactions: ISBN, number of books sold, price per book 13 std::cin >> data1.bookNo >> data1.units_sold >> price; 14 // calculate total revenue from price and units_sold 15 data1.revenue = data1.units_sold * price; 16 17 // read the second transaction 18 std::cin >> data2.bookNo >> data2.units_sold >> price; 19 data2.revenue = data2.units_sold * price; 20 21 // code to check whether data1 and data2 have the same ISBN 22 // and if so print the sum of data1 and data2 23 if (data1.bookNo == data2.bookNo) { 24 unsigned totalCnt = data1.units_sold + data2.units_sold; 25 double totalRevenue = data1.revenue + data2.revenue; 26 27 // print: ISBN, total sold, total revenue, average price per book 28 std::cout << data1.bookNo << " " << totalCnt 29 << " " << totalRevenue << " "; 30 if (totalCnt != 0) 31 std::cout << totalRevenue/totalCnt << std::endl; 32 else 33 std::cout << "(no sales)" << std::endl; 34 35 return 0; // indicate success 36 } else { // transactions weren't for the same ISBN 37 std::cerr << "Data must refer to the same ISBN" 38 << std::endl; 39 return -1; // indicate failure 40 } 41 }
- 读入data1和data2的代码
- 检查data1和data2的ISBN是否相同
- 如相同，求data1和data2的和