#include <iostream>
#include "include/Sales_item.h"

using std::cerr;
using std::cin;
using std::cout;
using std::endl;

auto sum(int lo, int hi)
{
 int sum = 0;
 while (lo <= hi)
 sum += lo++;
 return sum;
}

void print_range(int lo, int hi)
{
 if (lo > hi)
 {
 print_range(hi, lo);
 return;
 }
 for (int i = lo; i != hi; ++i)
 cout << i << " ";
}

int main(int argc, char *argv[])
{
 // 输出
 std::cout << "Hello CPP!" << std::endl;
 std::cout << "Sum of 50 to 100 inclusive is: " << sum(50, 100) << std::endl;

 // 循环
 int i = 10;
 while (i >= 0)
 {
 std::cout << i-- << " " << std::endl;
 }

 int sum = 0;
 for (int val = 1; val <= 10; ++val)
 {
 sum += val;
 std::cout << "Sum of 1 to 10 inclusive is " << sum << std::endl;
 }

 // Class
 // for (Sales_item item; cin >> item; cout << item << endl);
 Sales_item book;
 std::cin >> book;
 std::cout << book << std::endl;

 // test 0-201-70353-X 4 24.99

 // 输入输出
 int low = 0, high = 0;
 cout << "please input two integers:\n";
 cin >> low >> high;
 print_range(low, high);

 return 0;
}

int isbn()
{
 Sales_item item1, item2;
 cin >> item1 >> item2;
 if (item1.isbn() == item2.isbn())
 cout << item1 + item2 << endl;
 else
 cerr << "Different ISBN." << endl;
 return 0;
}