我使用我的导师制定的指导方针编写了这个程序。一旦我最终修复了所有的拼写错误和语法错误，我就尝试编译程序并恢复了 5 个链接器错误。据我所知，该程序绝对没有任何问题，所以我想知道你们中是否有人能指出我正确的方向。
谢谢
我收到的链接器错误：
Error 2 error LNK2019: unresolved external symbol "void __cdecl write_records(class SalesRecord *)" (?write_records@@YAXPAVSalesRecord@@@Z) referenced in function _main C:\Users\Home\Documents\Visual Studio 2010\Projects\Assignment10\Assignment10\Assign10.obj
Error 3 error LNK2019: unresolved external symbol "void __cdecl calc_discounts(class SalesRecord *)" (?calc_discounts@@YAXPAVSalesRecord@@@Z) referenced in function _main C:\Users\Home\Documents\Visual Studio 2010\Projects\Assignment10\Assignment10\Assign10.obj
Error 4 error LNK2019: unresolved external symbol "class SalesRecord * __cdecl read_records(class std::basic_ifstream<char,struct std::char_traits<char> > &)" (?read_records@@YAPAVSalesRecord@@AAV?$basic_ifstream@DU?$char_traits@D@std@@@std@@@Z) referenced in function _main C:\Users\Home\Documents\Visual Studio 2010\Projects\Assignment10\Assignment10\Assign10.obj
Error 5 error LNK1120: 3 unresolved externals C:\Users\Home\Documents\Visual Studio 2010\Projects\Assignment10\Debug\Assignment10.exe 1
//Author William Lovejoy
//Assignment 10
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdlib>
#include <string>
using namespace std;
const int MAX_FILE_NAME = 35;
const int MAX_ID_LEN = 10;
const int MAX_NAME_LEN = 30;
const double DISCOUNT = 0.10;
const double DISCOUNT_BREAK_POINT = 10;
class SalesRecord;
typedef SalesRecord * SalesRecordPtr;
class SalesRecord
{ private:
char item_id[MAX_ID_LEN + 1];
char item_name[MAX_NAME_LEN + 1];
int quantity_sold;
double regular_price;
double discount_price;
double total_price;
SalesRecord *next;
public:
SalesRecord();
void read(ifstream& in);
void calc_discount_price();
void write(ostream & os) const;
int quantity();
double total_for_item();
bool operator<(const SalesRecord& right) const;
friend SalesRecordPtr read_records (ifstream& in);
friend void calc_discounts(SalesRecordPtr head);
friend void write_records(SalesRecordPtr head);
friend void append(SalesRecordPtr& head, SalesRecord& thisrecord);
friend void delete_records(SalesRecordPtr& head);
};
void open_input(ifstream& input, char name[]);
void open_output(ofstream& output, char name[]);
int main()
{ char again;
int num_records;
char infilename[MAX_FILE_NAME + 1];
ifstream in;
SalesRecordPtr records = NULL;
do
{ open_input(in, infilename);
records = read_records(in);
in.close();
if (records != NULL)
{ calc_discounts(records);
write_records(records);
delete_records(records);
}
else
{ cout << "\n\n\aNo data in file: " << infilename << endl;
}
cout << "\nDo you want to process another file (Y/N)? ";
cin >> again;
cin.ignore(1, '\n');
}
while ( again == 'y' || again == 'Y');
cout << "\n\n***** END OF PROGRAM ******\n";
return 0;
}
void open_input(ifstream& input, char name[])
{ int count = 0;
do
{ count++;
if (count != 1)
{ cout << "\n\aInvalid file name or file does not exist. Please try again."
<< endl;
}
cout << "\nEnter the input file name (maximum of " << MAX_FILE_NAME
<< " characters please)\n:> ";
cin.get(name, MAX_FILE_NAME + 1);
cin.ignore(81, '\n');
input.clear();
} while (input.fail() );
}
void open_output(ofstream& output, char name[])
{ int count = 0;
do
{ count++;
if (count != 1)
{ cout << "\n\aInvalid file name or file does not exist. Please try again."
<< endl;
}
cout << "\nEnter the input file name (maximum of " << MAX_FILE_NAME
<< " characters please)\n:> ";
cin.get(name, MAX_FILE_NAME + 1);
cin.ignore(81, '\n');
output.clear();
output.open(name);
} while (output.fail() );
}
bool SalesRecord::operator<(const SalesRecord& right) const
{ if (_stricmp(item_name, right.item_name) < 0) return true;
else return false;
}
SalesRecord::SalesRecord()
{ next = NULL;
}
void SalesRecord::read(ifstream& in)
{ in.get(item_id, MAX_ID_LEN +1);
while (in.get() != '\n');
in.get(item_name, MAX_NAME_LEN +1);
while (in.get() != '\n');
in >> quantity_sold >> regular_price;
while (in.get() != '\n');
}
void SalesRecord::calc_discount_price()
{ double discount_rate;
if (quantity_sold < DISCOUNT_BREAK_POINT)
discount_rate = 0.0;
else
discount_rate = DISCOUNT;
discount_price = regular_price - (discount_rate * regular_price);
total_price = quantity_sold * discount_price;
}
void SalesRecord::write(ostream & os) const
{ os.setf(ios::fixed); os.setf(ios::showpoint); os.precision(2);
os << item_id << "\n" << item_name << "\n"
<< quantity_sold << " " << discount_price << " "
<< total_price << endl;
}
void append(SalesRecordPtr& head, SalesRecord& thisrecord)
{ SalesRecord * new_record = NULL;
SalesRecord * last = NULL;
new_record = new SalesRecord;
if (new_record == NULL)
{ cout << "\aCan not allocate memory!";
exit(1);
}
*new_record = thisrecord;
new_record->next = NULL;
if (head == NULL)
{ head = new_record;
}
else
{ last = head;
while ( last->next != NULL)
{ last = last->next;
}
last->next = new_record;
}
}
void delete_records(SalesRecordPtr& head)
{ SalesRecord * current = NULL;
SalesRecord * deadmeat = NULL;
current = head;
while (current != NULL)
{ deadmeat = current;
current = current->next;
delete deadmeat;
}
head = NULL;
}