# include & ltiomanip & gt
# include & lt string & gt
# include & ltfstream & gt// input/output file stream class
Use namespace std
const int Maxr = 100； //The most readers
const int Maxb = 100； //The most books
const int max bor = 5； //Each reader can borrow up to five books.
//reader class, which describes the information of readers.
Class reader
{
Private:
Int label; //Delete tag 1: Deleted 0: Not deleted.
Int number; //Reader number
Character name [10]; //Reader's name
int bor book[max bor]； //Borrow books
Public:
Reader() {}
char * getname(){ return name； }//Get the name
int gettag(){ return tag； }//Get delete tag
int getno(){ return no； }//Get the reader number
Void setname(char na[]) // Set the name.
{
Strcpy (name, not applicable);
}
void del book(){ tag = 1； }//Set the delete flag 1: Deleted 0: Not deleted.
Void addreader(int n, char *na)// Add reader.
{
tag = 0；
no = n；
Strcpy (name, not applicable);
for(int I = 0； I & ltMaxbori++)
bor book[I]= 0；
}
Void borrowbook(int bookid)// borrowing operation
{
for(int I = 0； I & ltMaxbori++)
{
if (borbook[i]==0)
{
bor book[I]= bookid；
Return;
}
}
}
Int retbook(int bookid)// book return operation
{
for(int I = 0； I & ltMaxbori++)
{
if(borbook[i]==bookid)
{
bor book[I]= 0；
Returns1;
}
}
Returns 0;
}
Void disp()// Read the reader information.
{
cout & lt& ltsetw(5)& lt； & lt No< setw (10) < & lt name & lt& lt "Borrowing number: [";
for(int I = 0； I & ltMaxbori++)
if(borbook[i]！ =0)
cout & lt& ltbor book[I]& lt； & lt"|";
cout & lt& lt"]" & lt； & ltendl
}
};
//reader class library, to realize the establishment of readers' personal data.
Category database
{
Private:
Int top// reader record pointer
Reader read [maxr]; //Reader record
Public:
The RDatabase() // constructor reads reader.txt into read[].
{
Reader s;
top =- 1；
The fstream file ("reader.txt", IOs:: in); //Open an input file
while ( 1)
{
file . read((char *)& amp； s，sizeof(s))；
If (! File) interrupt;
top++；
read[top]= s；
}
file . close()； //close reader.txt
}
Void clear()// Delete all reader information.
{
top =- 1；
}
Int addreader(int n, char *na)// When adding readers, check whether they exist.
{
reader * p = query(n)；
if (p==NULL)
{
top++；
Read [top]. addreader(n，na)；
Returns1;
}
Returns 0;
}
Reader *query(int readerid)// Search by number.
{
for(int I = 0； I<= topi++)
If (read [me]. getno()= = readerid & amp； & amp
Read [me]. gettag()==0)
{
Change & to [i];
}
Returns NULL
}
Void disp() // Output all reader information.
{
for(int I = 0； I<= topi++)
Read [me]. disp()；
}
void reader data()； //Reader Library Maintenance
~RDatabase() // destructor, write read[] to the reader.txt file.
{
The fstream file ("reader.txt", IOs:: out);
for(int I = 0； I<= topi++)
If (read [me]. gettag()==0)
file . write((char *)& amp； read[i]，sizeof(read[I])；
file . close()；
}
};
void RDatabase::readerdata()
{
Char selection;
char rname[20]；
int readerid
reader * r；
And (choose! ='0')
{
Cout & lt& lt" \ n \ n \ t \ tReader maintenance \ n \ n \ t1is newly added \ n \ n \ t \ t 2 has been changed \ n \ n \ t \ t 3 has been deleted \ n
CIN & gt； & gt selection;
Switch (selection)
{
Case "1":
Cout & lt& lt "Enter the card reader number:";
CIN & gt； & gtreaderid
Cout & lt& lt "Enter the reader name:";
CIN & gt； & gtrname
addreader (readerid，rname)；
Break;
Case "2":
Cout & lt& lt "Enter the card reader number:";
CIN & gt； & gtreaderid
r = query(readerid)；
if (r==NULL)
{
Cout & lt& lt "Readers don't exist"
Break;
}
Cout < < "Enter a new name:";
CIN & gt； & gtrname
r-& gt； set name(rname)；
Break;
Case "3":
Cout & lt& lt "Enter the card reader number:";
CIN & gt； & gtreaderid
r = query(readerid)；
if (r==NULL)
{
Cout & lt& lt "Readers don't exist"
Break;
}
r-& gt； del book()；
Break;
Case "4":
Cout & lt& lt "Read in the reader number:";
CIN & gt； & gtreaderid
r = query(readerid)；
if (r==NULL)
{
Cout & lt& lt "Readers don't exist"
Break;
}
r-& gt； disp()；
Break;
Case "5":
disp()；
Break;
Case "6":
clear()；
Break;
Default value: cout & lt& lt "entered incorrectly, please re-enter:"; Break;
}
}
}
//Book category, which realizes the description, book number, title, lending and return of books.
Classroom books
{
Private:
Int label; //Delete tag 1: Deleted 0: Not deleted.
Int number; //Book number
char name[20]； //Book title
Int onshelf// Do you want to borrow 1: Borrow 2: Borrow?
Public:
Book(){}
char * getname(){ return name； }//Get the name
int getno(){ return no； }//Get the book number
int gettag(){ return tag； }//Get delete tag
Void setname(char na[])// Set the title of the book.
{
Strcpy (name, not applicable);
}
void del book(){ tag = 1； }//Delete books
Voiddaddbook (int n, char *na)// Add books.
{
tag = 0；
no = n；
Strcpy (name, not applicable);
on shelf = 1；
}
Int borrowbook()// borrowing operation
{
if(on self = = 1)
{
on shelf = 0；
Returns1;
}
Returns 0;
}
Void retbook()// book return operation
{
on shelf = 1；
}
Void disp()// output books
{
cout & lt& ltsetw(6)& lt； & lt No< setw (18) < & lt name & lt& ltsetw( 10)
& lt& lt(onshelf== 1？ On the shelf: "borrowed") < & ltendl
}
};
//Library class, which can maintain, search and delete books.
Class b database
{
Private:
Int top// book record pointer
book book[Maxb]； //Book records
Public:
The BDatabase()// constructor reads book.txt into book[].
{
Book b;
top =- 1；
The fstream file ("book.txt", IOs:: in);
while ( 1)
{
file . read((char *)& amp； b，sizeof(b))；
If (! File) interrupt;
top++；
book[top]= b；
}
file . close()；
}
Void clear()// Delete All
{
top =- 1；
}
Int addbook(int n, char *na)// Add books.
{
book * p = query(n)；
if (NULL==p)
{
top++；
Book [top]. addbook(n，na)；
Returns1;
}
Returns 0;
}
Book *query(int bookid)// find books.
{
for(int I = 0； I<= topi++)
If (book [me]. getno()= = bookid & amp； & Book [me]. gettag()==0)
{
Return to & book [i];
}
Returns NULL
}
void book data()； //Library maintenance
Invalid display ()
{
for(int I = 0； I<= topi++)
If (book [me]. gettag()==0)
Book [me]. disp()；
}
~BDatabase()// destructor, and write book[] into the book.txt file.
{
The fstream file ("book.txt", IOs:: out);
for(int I = 0； I<= topi++)
If (book [me]. gettag()==0)
file . write((char *)& amp； book[i]，sizeof(book[I])；
file . close()；
}
};
void BDatabase::bookdata()
{
Char selection;
char bname[40]；
int bookid
Book * b；;
And (choose! ='0')
{
Cout & lt& lt" \ n \ n \ n \ t \ t \ Library maintenance "< & ltendl & lt& ltendl
Cout & lt& lt" \t\t 1 was newly added \n \t\t2 was changed \n\t\t3 was deleted \n\t\t4 was searched \n\t\t5 was displayed \n\t\t6 was completely deleted \
CIN & gt； & gt selection;
Switch (selection)
{
Case "1":
Cout & lt& lt "Enter the book number:"
CIN & gt； & gtbookid
Cout & lt& lt "Enter a title:"
CIN & gt； & gtbname
addbook(bookid，bname)；
Break;
Case "2":
Cout & lt& lt "Enter the book number:"
CIN & gt； & gtbookid
B = BookID;
if (b==NULL)
{
Cout & lt& lt "This book doesn't exist"
Break;
}
Cout & lt& lt "Enter a new title:"
CIN & gt； & gtbname
b-& gt； set name(bname)；
Break;
Case "3":
Cout & lt& lt "Read the book number:"
CIN & gt； & gtbookid
B = BookID;
if (b==NULL)
{
Cout & lt& lt "This book doesn't exist"
Break;
}
b-& gt； del book()；
Break;
Case "4":
Cout & lt& lt "Read the book number:"
CIN & gt； & gtbookid
B = BookID;
if (b==NULL)
{
Cout & lt& lt "This book doesn't exist"
Break;
}
b-& gt； disp()；
Break;
Case "5":
disp()；
Break;
Case "6":
clear()；
Break;
Default value: cout & lt& lt "entered incorrectly, please re-enter:";
}
}
}
//The realization of the main () function and the guidance of the main interface of the program.
void main()
{
Char selection;
int bookid，readerid
RDatabase ReaderDB
reader * r；
B database BookDB
Book * b；;
And (choose! ='0')
{
Cout & lt< endl & lt<< "\ t \ t \ library management system \ n \ n \ n”；
Cout & lt< "\ t \ t1borrowing books \ n \ n \ t \ T2 Returning books \ n \ n \ t \ t3Library maintenance \ n \ n \ t \ t4Reader maintenance \ n \ n \ n \.
CIN & gt； & gt selection;
Switch (selection)
{
Case "1":
Cout & lt& lt borrows the reader number:;
CIN & gt； & gtreaderid
Cout & lt& lt "ISBN:";
CIN & gt； & gtbookid
r = readerdb . query(readerid)； //Search by number
if (NULL==r)
{
Cout & lt& lt "Readers don't exist, books can't be borrowed" < & ltendl
Break;
}
b = bookdb . query(bookid)；
if (b==NULL)
{
Cout & lt& lt "This book doesn't exist, so you can't borrow it" < & ltendl.
Break;
}
if(b-& gt； borrowbook()==0)
{
Cout & lt& lt "This book has been lent out, so you can't borrow it any more" < & ltendl.
Break;
}
r-& gt； Borrowing books (b-> getno())；
Break;
Case "2":
Cout & lt& lt "returns the book \ nReader number:";
CIN & gt； & gtreaderid
Cout & lt& lt "ISBN:";
CIN & gt； & gtbookid
r = readerdb . query(readerid)；
if (r==NULL)
{
Cout & lt& lt "The reader does not exist, so the book cannot be returned" < & ltendl.
Break;
}
b = bookdb . query(bookid)；
if (b==NULL)
{
Cout & lt& lt "The book does not exist and cannot be returned" < & ltendl
Break;
}
b-& gt； ret book()；
r-& gt； retbook(b-& gt； getno())；
Break;
Case "3":
bookdb . book data()；
Break;
Case "4":
reader db . reader data()；
Break;
Default value: cout & lt& lt "entered incorrectly, please re-enter:";
}
}
}