#include<iostream.h>
#include<stdlib.h>
#include<stdio.h>
#include<fstream.h>
#include<conio.h>
class
db
{
public:
int
rno,marks,ri;
char name[10];
};
class
NODE
{
db s,s1;
public:
int data,ri;
NODE *next;
void create();
void append();
void display();
int hashfun(int);
void hashcreate();
void hashdisp();
void search();
};
NODE
*temp,*nw,*head[10];
void
NODE::create()
{
fstream obj;
s.ri=0;
obj.open("a.txt",ios::out);
if(obj==NULL)
{
cout<<"\nFile is not
open";
exit(0);
}
cout<<"\nFile created
successfully";
obj.close();
}
void
NODE::append()
{
fstream obj;
obj.open("a.txt",ios::app);
if(obj==NULL)
{
cout<<"\nFile is not
open";
exit(0);
}
cout<<"\nEnter name:";
cin>>s.name;
cout<<"\nEnter roll no:";
cin>>s.rno;
cout<<"\nEnter marks:";
cin>>s.marks;
s.ri++;
obj.write((char *)&s,sizeof(s));
obj.close();
}
void
NODE::display()
{
fstream obj;
obj.open("a.txt",ios::in);
if(obj==NULL)
{
cout<<"\nFile is not
open";
exit(0);
}
cout<<"\nThe database
is:\n\nName\tRoll no\tMarks\n";
while(obj.read((char *)&s,sizeof(s)))
{
cout<<"\n"<<s.name<<"\t"<<s.rno<<"\t"<<s.marks;
}
obj.close();
}
int
NODE::hashfun(int x)
{
int value;
value=x%10;
return(value);
}
void
NODE::hashcreate()
{
fstream obj;
for(int i=0;i<10;i++)
{
head[i]=new(NODE);
head[i]->data=i;
head[i]->next=NULL;
}
obj.open("a.txt",ios::in);
if(obj==NULL)
{
cout<<"\nFile is not
open";
exit(0);
}
while(obj.read((char *)&s1,sizeof(s1)))
{
int hno=hashfun(s1.rno);
nw=new(NODE);
nw->next=NULL;
nw->data=s1.rno;
nw->ri=s1.ri;
temp=head[hno];
while(temp->next!=NULL)
temp=temp->next;
temp->next=nw;
}
obj.close();
}
void
NODE::hashdisp()
{
for(int i=0;i<10;i++)
{
temp=head[i];
while(temp!=NULL)
{
cout<<temp->data<<"->";
temp=temp->next;
}
cout<<"NULL\n";
}
}
void
NODE::search()
{
int cno,l=0,x;
ifstream obj;
cout<<"\nEnter the record to
search:";
cin>>x;
cno=hashfun(x);
temp=head[cno]->next;
while(temp!=NULL)
{
if(temp->data==x)
{
l=temp->ri;
break;
}
temp=temp->next;
}
if(l==0)
cout<<"\nRecord not
found";
else
{
obj.open("a.txt",ios::in);
if(obj==NULL)
{
cout<<"\nFile is not
open";
exit(0);
}
obj.seekg(0,ios::beg);
long offset=(l-1)*sizeof(s1);
obj.seekg(offset);
obj.read((char *)&s1,sizeof(s1));
cout<<"\nThe database
is:\n\nName\tRoll no\tMarks";
cout<<"\n\n"<<s1.name<<"\t"<<s1.rno<<"\t"<<s1.marks;
obj.close();
}
}
void
main()
{
int ch,srch;
NODE a;
clrscr();
do
{
cout<<"\n\tMenu\n1.Create\n2.Append\n3.Display\n4.Hash
create";
cout<<"\n5.Hash
display\n6.Search\n7.Exit\nEnter your choice:";
cin>>ch;
switch(ch)
{
case 1:
a.create();
break;
case 2:
a.append();
break;
case 3:
a.display();
break;
case 4:
a.hashcreate();
break;
case 5:
a.hashdisp();
break;
case 6:
a.search();
break;
case 7:
exit(0);
break;
}
}while(ch!=7);
getch();
}
-----------------------------------Output-------------------------------
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:1
File
created successfully
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:2
Enter
name:n
Enter
roll no:75
Enter
marks:87
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:2
Enter
name:s
Enter
roll no:76
Enter
marks:80
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:3
The
database is:
Name Roll no Marks
n 75
87
s 76
80
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:4
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:5
0->NULL
1->NULL
2->NULL
3->NULL
4->NULL
5->75->NULL
6->76->NULL
7->NULL
8->NULL
9->NULL
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:6
Enter
the record to search:75
The
database is:
Name Roll no Marks
n 75
87
Menu
1.Create
2.Append
3.Display
4.Hash
create
5.Hash
display
6.Search
7.Exit
Enter
your choice:7
This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.