fatal error C1083: Cannot open include file: 'Sales_item.hpp': No such file or d解决方案

fatal error C1083: Cannot open include file: 'Sales_item.hpp': No such file or d
#include<iostream>
#ifndef SALESITEM_H
#define SALESITEM_H
#include<string>
class Sales_item
 {public:
std::istream& input(std::istream& in);
std::istream& output(std::istream& out) const;
double avg_price() const;
bool same_isbn(const Sales_item &rhs) const
{return isbn==rhs.isbn;}
Sales_item::Sales_item():units_sold(0),revenue(0.0)
{}
private:
std::string isbn;
unsigned units_sold;
double revenue;
};
#endif

#include"Sales_item.hpp"
std::istream& Sales_item::input(std::istream& in)
{double price;
in>>isbn>>units_sold>>revenue;
if(in)
revenue=units_sold*price;
else {units_sold=0;
revenue=0.0;}
return in;}
std::ostream& Sales_item::output(std::ostream& out) const
{out<<isbn<<"\t"<<units_sold<<"\t"<<revenue<<"\t"<<avg_price();
return out;}
double Sales_item::avg_price() const
{if (units_sold)
return revenue/units_sold;
else return 0;}
#include<isotream>
#include"Sales_item.hpp"
using namespace std;
int main()
{Sales_item item;
cout<<"shuru"<<endl;
whlie(item.input(cin))
{cout<<"shuchu"<<endl;
item.output(cout)
cout<<endl;
}return 0;}
我想问一下cpp和hpp应该放在什么位置

------解决方案--------------------
VC?放在同一个工程的同一个文件夹下面.
------解决方案--------------------
你工程项目的 debug文件夹 一个目录