BNMIT file structure lab manual

Vidyaya Amrutham Ashnuthe

Department of Information Science & Engineering

FILE STRUCTURE LABORATORY MANUAL

SUBCODE: 06ISL67, VI SEMESTER B.E

BNM Institute of Technology

(Approved by AICTE & Affiliated to VTU, Karnataka)(An ISO 9001:2008 Certified Institution)

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VTU LAB SYLLABUS

FILE STRUCTURE LABORATORY

Subject Code : 06ISL67 IA Marks : 25

No. of Practical

Hours/Week

: 03 Exam

Hours

: 03

Total No. of Practical

Hours

: 42 Exam

Marks

: 50

1. Write a C++ program to read series of names, one per line, from standard input and

write these names spelled in reverse order to the standard output using I/O

redirection and pipes. Repeat the exercise using an input file specified by the user

instead of the standard input and using an output file specified by the user instead

of the standard output.

2. Write a C++ program to read and write student objects with fixed-length records

and the fields delimited by “|”. Implement pack ( ), unpack ( ), modify ( ) and

search ( ) methods.

3. Write a C++ program to read and write student objects with Variable - Length

records using any suitable record structure. Implement pack ( ), unpack ( ), modify

( ) and search ( ) methods.

4. Write a C++ program to write student objects with Variable - Length records using

any suitable record structure and to read from this file a student record using

RRN.

5. Write a C++ program to implement simple index on primary key for a file of

student objects. Implement add ( ), search ( ), delete ( ) using the index.

BNMIT/ISE/2012/VI/ File Structure laboratory Page 2

6. Write a C++ program to implement index on secondary key, the name, for a file

of student objects. Implement add ( ), search ( ), delete ( ) using the secondary

index.

7. Write a C++ program to read two lists of names and then match the names in the

two lists using Cosequential Match based on a single loop. Output the names

common to both the lists.

8. Write a C++ program to read k Lists of names and merge them using k-way merge

algorithm with k = 8.

9. Write a C++ program to implement B-Tree for a given set of integers and its

operations insert ( ) and search ( ). Display the tree.

10. Write a C++ program to implement B+ tree for a given set of integers and its

operations insert ( ), and search ( ). Display the tree.

11. Write a C++ program to store and retrieve student data from file using hashing.

Use any collision resolution technique.

12. Write a C++ program to reclaim the free space resulting from the deletion of

records using linked lists.


ContentsVTU LAB SYLLABUS....................................................................................2

Program 1..................................................................................................5

Program 2..................................................................................................9

Program 3................................................................................................19

Program 4................................................................................................28

Program 5................................................................................................34

Program 6................................................................................................43

Program 7................................................................................................60

Progrm 8..................................................................................................64

Program 9................................................................................................69

Program 10..............................................................................................80

Program 11..............................................................................................94

Program 12............................................................................................101


Program 1

Write a C++ program to read series of names, one per line, from standard input

and write these names spelled in reverse order to the standard output using I/O

redirection and pipes. Repeat the exercise using an input file specified by the

user instead of the standard input and using an output file specified by the user

instead of the standard output.

#include<iostream.h>

#include<conio.h>

#include<process.h>

#include<string.h>

#include<fstream.h>

class names

{

public:char name[50];

};

void reverse(ofstream &out,char name[255])

{

char *rev;

rev=name+strlen(name)-1;

while(rev>=name)

{

cout<<*rev;

out<<*rev;

rev--;

}

cout<<endl;

out<<"\n";


}

void main()

{

names n[10];

clrscr();

ofstream out;

out.open("file.txt",ios::out|ios::app|ios::trunc);

int m;

cout<<"enter the no. of names to be entered\n";

cin>>m;

for(int i=0;i<m;i++)

{

cout<<"enter name";

cin>>n[i].name;

cout<<"the name in reverse order";

reverse(out,n[i].name);

}

out.close();

ifstream in;

in.open("file.txt",ios::in|ios::binary);

ofstream outf;

outf.open("f1.txt",ios::out|ios::app|ios::trunc);

char ch[255];

cout<<"names from files\n";

while(in)

{

in.getline(ch,255);

if(in)


reverse(outf,ch);

}

cout<<endl;

in.close();

outf.close();

in.open("f1.txt",ios::in|ios::binary);

outf.open("f2.txt",ios::out|ios::app|ios::trunc);

cout<<"reverse order from files\n";

while(in)

{

in.getline(ch,255);

if(in)

reverse(outf,ch);

}

in.close();

outf.close();

getch();

}

Output:

Enter the no. of names to be entered

5

Enter name

priya

The name in reverse order

ayirp

Enter name

padma



amdap

Enter name

ajit


tija

Enter name

sohan


nahos

Enter name

dilip


pilid

The names from files (f1.txt)

priya

padma

ajit

soni

dilip

Reverse order from files (f2.txt)

ayirp

amdap

tija

nahos

pilid


Program 2

Write a C++ program to read and write and student objects with fixed length

records and the fields delimited by “|”.implement pack(),unpack(),modify() and

search() methods.

#include<stdio.h>

#include<conio.h>


#include<stdlib.h>

#include<fstream.h>

#include<string.h>

class student

{

public:char name[25],usn[15],branch[15],buffer[45];

};

student s,s1[100];

char extra[45];

int i,no=0,mode=0;

void pack()

{

fstream app;

if(mode==0)

app.open("st1.txt",ios::app);

else

app.open("st1.txt",ios::out);

if(!app)

{


cout<<"cant open the file in output mode";

getch();

exit(0);

}

strcpy(s.buffer,s.name);

strcat(s.buffer,"|");

strcat(s.buffer,s.usn);


strcat(s.buffer,s.branch);

int count=strlen(s.buffer);

for(int k=0;k<45-count;k++)


strcat(s.buffer,"\n");

app<<s.buffer;

app.close();

}

void unpack()

{

fstream in;

in.open("st1.txt",ios::in);

i=0,no=0;

if(!in)

{

cout<<"cant open the file in input mode";

getch();

exit(0);

}

while(!in.eof())


{

in.getline(s1[i].name,15,'|');

in.getline(s1[i].usn,15,'|');

in.getline(s1[i].branch,15,'|');

in.getline(extra,45,'\n');

no++;

i++;

}

in.close();

}

void write()

{

cout<<"\n enter the student name\n";

cin>>s.name;

cout<<"enter the student usn\n";

cin>>s.usn;

cout<<"enter the student branch\n";

cin>>s.branch;

pack();

mode=0;

}

void search()

{

char usn[15],extra[45];

cout<<"enter the usn to search=";

cin>>usn;

unpack();

for(i=0;i<no;i++)


{

if(strcmp(s1[i].usn,usn)==0)

{

cout<<"\nrecord found";

cout<<"\n"<<s1[i].name<<"\t"<<s1[i].usn<<"\t"<<s1[i].branch;

getch();

return;

}

}

cout<<"record not found";

getch();

return;

}

void display()

{

cout<<"name\t\t usn\t\t branch\n\n";

unpack();

for(int i=0;i<no;i++)

cout<<"\n\n"<<s1[i].name<<"\t\t"<<s1[i].usn<<"\t\t"<<s1[i].branch;

getch();

}

void modify()

{

char usn[15],buffer[15],extra[45];

cout<<"enter the usn to search\n";

cin>>usn;

unpack();no--;

for(int j=0;j<no;j++)


{

if(strcmp(usn,s1[j].usn)==0)

{

cout<<"the old values of the record are with

usn"<<usn<<"are";

cout<<"\nname="<<s1[j].name;

cout<<"\nusn="<<s1[j].usn;

cout<<"\nbranch="<<s1[j].branch;

cout<<"enter the new values\n";

cout<<"\nname=";

cin>>s1[j].name;

cout<<"\nusn=";

cin>>s1[j].usn;

cout<<"\nbranch=";

cin>>s1[j].branch;

break;

}

}

if(j==no)

{

cout<<"the record with usn is not present";

getch();

return;

}

mode=1;

for(j=0;j<no;j++)

{

strcpy(s.name,s1[j].name);


strcpy(s.usn,s1[j].usn);

strcpy(s.branch,s1[j].branch);

pack();

mode=0;

}

cout<<"record modified\n";

}

void main()

{

clrscr();

int choice;

for(;;)

{

//clrscr();

cout<<"\n0:exit";

cout<<"\n1:write";

cout<<"\n2:display";

cout<<"\n3:modify";

cout<<"\n4:search";

cout<<"enter u choice\n";

cin>>choice;

switch(choice)

{

case 1:write();

break;

case 2:display();

break;

case 3:modify();


break;

case 4:search();

break;

case 0:exit(0);

default:cout<<"\ninvalid input";

break;

}

}

}

Output:

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

1

Enter the student name

Karthik

Enter the student USN

1bg09is015

Enter the student branch

Ise

0: Exit

1: write

2: Display

3: Modify


4: Search

Enter your choice

1


Dhanvi


1bg09is007


Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

2

Name USN Branch

Karthik 1bg09is015 Ise

Dhanvi 1bg09is007 Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

3

Enter the USN to Modify

1bg09is007


Record found

The old values of the record with usn 1bg09is007 are

USN=1bg09is007

Name=Dhanvi

Branch=ise

Enter new values

Name=dhruva

USN=1bg09is023

Branch=ise

Record modified

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

4

Enter the usn to search

1bg09is023

Record found

Dhruva

1bg09is023

Ise

0: Exit

1: write

2: Display

3: Modify

4: Search


Enter your choice

0

Output from text file

karthik|1bg09is015|ise|||||||||||||||||||||||

dhruva|1bg09is023|ise||||||||||||||||||||||||


Program 3

Write a C++ program to read and write and student objects with variable length

records using any suitable record structure. Implement pack(),unpack(),modify()

and search() methods.

#include<stdio.h>

#include<conio.h>


#include<stdlib.h>

#include<fstream.h>

#include<string.h>

class student

{


};

student s,s1[100];

char extra[45];

int i,no=0,mode=0;

void pack()

{

fstream app;

if(mode==0)


else


if(!app)

{



getch();

exit(0);

}






//int count=strlen(s.buffer);

//for(int k=0;k<45-count;k++)

//strcat(s.buffer,"|");


app<<s.buffer;

app.close();

}

void unpack()

{

fstream in;


i=0,no=0;

if(!in)

{


getch();

exit(0);

}

while(!in.eof())

{




in.getline(s1[i].branch,15,'\n');

//in.getline(extra,45,'\n');

no++;

i++;

}

in.close();

}

void write()

{


cin>>s.name;


cin>>s.usn;


cin>>s.branch;

pack();

mode=0;

}

void search()

{


cout<<"enter the usn to search=";

cin>>usn;

unpack();

for(i=0;i<no;i++)

{


if(strcmp(s1[i].usn,usn)==0)

{



getch();

return;

}

}


getch();

return;

}

void display()

{

cout<<"name\t\t usn\t\t branch\n\n";

unpack();


cout<<"\n\n"<<s1[i].name<<"\t\t"<<s1[i].usn<<"\t\t"<<s1[i].branch;

getch();

}

void modify()

{

char usn[15],buffer[15],extra[45];

cout<<"enter the usn to search\n";

cin>>usn;

unpack();no--;

for(int j=0;j<no;j++)

{


if(strcmp(usn,s1[j].usn)==0)

{

cout<<"the old values of the record are with usn" <<usn << " are";

cout<<"\nname="<<s1[j].name;

cout<<"\nusn="<<s1[j].usn;

cout<<"\nbranch="<<s1[j].branch;

cout<<"enter the new values\n";

cout<<"\nname=";

cin>>s1[j].name;

cout<<"\nusn=";

cin>>s1[j].usn;

cout<<"\nbranch=";

cin>>s1[j].branch;

break;

}

}

if(j==no)

{

cout<<"the record with usn is not present";

getch();

return;

}

mode=1;

for(j=0;j<no;j++)

{

strcpy(s.name,s1[j].name);

strcpy(s.usn,s1[j].usn);

strcpy(s.branch,s1[j].branch);


pack();

mode=0;

}

cout<<"record modified\n";

}

void main()

{

int choice;

for(;;)

{

clrscr();

cout<<"\n0:exit";

cout<<"\n1:write";

cout<<"\n2:display";

cout<<"\n3:modify";

cout<<"\n4:search";


cin>>choice;

switch(choice)

{

case 1:write();

break;

case 2:display();

break;

case 3:modify();

break;

case 4:search();

break;


case 0:exit(0);


break;

}

} }

Output:

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

1


Karthik


1bg09is015


Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

1


Dhanvi



1bg09is007


Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

2

Name USN Branch

Karthik 1bg09is015 Ise

Dhanvi 1bg09is007 Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

3

Enter the USN to Modify

1bg09is007

Record found

The old values of the record with usn 1bg09is007 are

USN=1bg09is007

Name=Dhanvi

Branch=ise


Enter new values

Name=dhruva

USN=1bg09is023

Branch=ise

Record modified

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

4

Enter the usn to search

1bg09is023

Record found

Dhruva

1bg09is023

Ise

0: Exit

1: write

2: Display

3: Modify

4: Search

Enter your choice

0

Output from file

karthik|1bg09is015|ise

dhruva|1bg09is023|ise


Program 4

Write a c++ program to write student objects with variable-length records using any sitable record structure and to read from this file a student record using RRN.

#include<stdio.h>

#include<conio.h>


#include<stdlib.h>

#include<fstream.h>

#include<string.h>

class student

{


};

student s,s1[100];

char extra[45];

int i,no=0,mode=0;

void pack()

{

fstream app;

if(mode==0)


else


if(!app)

{


getch();


exit(0);

}






//int count=strlen(s.buffer);

//for(int k=0;k<45-count;k++)

//strcat(s.buffer,"|");


app<<s.buffer;

app.close();

}

void unpack()

{

fstream in;


i=0,no=0;

if(!in)

{


getch();

exit(0);

}

while(!in.eof())

{




in.getline(s1[i].branch,15,'\n');

//in.getline(extra,45,'\n');

no++;

i++;

}

in.close();

}

void write()

{


cin>>s.name;


cin>>s.usn;


cin>>s.branch;

pack();

mode=0;

}

void search()

{


int rrn;

cout<<"enter the rrn to search=";

cin>>rrn;

unpack();

for(int i=0;i<no-1;i++)

{


if(rrn==i+1)

{



getch();

return;

}

}


getch();

return;

}

void main()

{

int choice;

for(;;)

{

clrscr();

cout<<"\n0:exit";

cout<<"\n1:write";

cout<<"\n2:search";


cin>>choice;

switch(choice)

{

case 1:write();

break;

case 2:search();


break;

case 0:exit(0);


break;

}

}

}

Output:

0: Exit

1: write

2: Search

Enter your choice

1


Satish


1bg09is055


Ise

0: Exit

1: write

2: Search

Enter your choice

1


divya


1bg09is408



Ise

0: Exit

1: write

2: Search

Enter your choice

2

Enter the RRN to search=1

Satish 1bg09is055 Ise

Enter the RRN to search=2

divya 1bg09is408 Ise

Enter your choice

0


Program 5

Write a C++ program to implement simple index on primary key for a file of student objects. Implement add(),search(),delete() using the index.

#include<stdio.h>#include<conio.h>

#include<string.h>


#include<process.h>

#include<values.h>

#include<fstream.h>

#include<stdlib.h>

class record

{

public:char name[20],usn[20],branch[20],ind[5];

}rec[20];

char st_no[5];

int no;

void pack()

{

fstream fle1,fle2;

fle1.open("i.txt",ios::out);

fle2.open("r.txt",ios::out);

if((!fle1)||(!fle2))

{

cout<<"cant open either\n";

getch();

exit(0);

}



{

fle1<<rec[i].usn<<"|"<< i<<"\n";

fle2<<i<<"|"<<rec[i].name<<"|"<<rec[i].usn<<"|"<<rec[i].branch<<"\n";

}

fle1.close();

fle2.close();

}

void unpack()

{

fstream fle2;

fle2.open("r.txt",ios::in);


{

fle2.getline(rec[i].ind,5,'|');

fle2.getline(rec[i].name,20,'|');

fle2.getline(rec[i].usn,20,'|');

fle2.getline(rec[i].branch,20,'\n');

}

fle2.close();

}

void search()

{

char name[20],usn[20],branch[20],ind[5];

unpack();


if(strcmp(st_no,rec[i].ind)==0)


{

cout<<"search sucess\n";

cout<<"\nname="<<rec[i].name<<"usn="<<rec[i].usn<<"bran="<<rec[i].branch<<"\n";

}

}

void delete_rec(char rt_no[])

{

int flag=1;

char name[20],usn[20],branch[20];


if(strcmp(rec[i].usn,rt_no)==0)

flag=i;

if(flag==-1)

{

cout<<"error\n";

getch();

exit(0);

}

if(flag==no)

{

no--;

cout<<"deleted\n";

pack();

return;

}

for(i=flag;i<no;i++)

{


rec[i]=rec[i+1];

no--;

cout<<"deleted\n";

pack();

return;

}

}

void main()

{

char st_usn[20],rt_usn[20];

fstream fle1,fle2;

char name[20],usn[20],branch[20],ind[5];

int i,flag,ch;

clrscr();

for(;;)

{

cout<<"1:add\n2:search\n3:delete\n4:display\n";

cout<<"enter your choice\n";

cin>>ch;

switch(ch)

{

case 1:cout<<"enter the no of records\n";

cin>>no;

cout<<"enter the details of students\n";

for(i=0;i<no;i++)

{

cout<<"name=";

cin>>rec[i].name;


cout<<"usn=";

cin>>rec[i].usn;

cout<<"branch=";

cin>>rec[i].branch;

}

pack();

break;

case 2:cout<<"enter thye usn u want to search\n";

cin>>st_usn;

//fstream fle1;

fle1.open("i.txt",ios::in);

if(!fle1)

{

cout<<"cant open the file\n";

getch();

exit(0);

}

flag=0;

for(i=0;i<no;i++)

{

fle1.getline(rt_usn,20,'|');

fle1.getline(st_no,5,'\n');

if(strcmp(rt_usn,st_usn)==0)

{

search();

flag=1;

}

}


if(!flag)

cout<<"not found\n";

fle1.close();

break;

case 3:cout<<"enter thye usn u want to delete\n";

cin>>st_usn;

fle1.open("i.txt",ios::in);

if(!fle1)

{


getch();

exit(0);

}

flag=0;

for(i=0;i<no;i++)

{

fle1.getline(rt_usn,20,'|');

fle1.getline(st_no,5,'\n');

if(strcmp(rt_usn,st_usn)==0)

{

delete_rec(rt_usn);

flag=1;

}

}

if(!flag)

cout<<"failure\n";

fle1.close();

break;


case 4:for(int i=0;i<no;i++)

{

cout<<"name="<<rec[i].name<<"usn="<<rec[i].usn<<"

branch="<<rec[i].branch<<"\n";

break;

default:exit(0);

break;

}

}

}

Output:

1: add

2: search

3: delete

4: display

Enter your choice

1

Enter the number of records

2

Enter the details of students

Name = anu

Usn = 1bg09is003

Branch = ise

Name= naveen

Usn = 1bg09is089

Branch = ise

1: add

2: search


3: delete

4: display

Enter your choice

4

Name= anu usn= 1bg09is003 branch=ise

Name= naveen usn= 1bg09is067 branch=ise

1: add

2: search

3: delete

4: display

Enter your choice

2

Enter the usn you want to search

1bg09is067

Search success

Name= naveen usn= 1bg09is067 branch=ise

1: add

2: search

3: delete

4: display

Enter your choice

2

Enter the usn you want to search

1bg09is006

Not found

1: add

2: search

3: delete


4: display

Enter your choice

3

Enter the usn you want to delete

1bg09is067

Deleted

1: add

2: search

3: delete

4: display

Enter your choice

4

Name= anu usn= 1bg09is003 branch=ise

Enter your choice

5.

Output from Index file

1bg09is003|0

1bg09is067|1

Output from Record file

0|anu|1bg09is003|ise

1|Naveen|1bg09is067|ise


Program 6

Write a C++ program to implement index on secondary key,the name,for a file of student objects.Implement add(),search(),delete() using the secondary index.


#include<stdio.h>

#include<fstream.h>

#include<stdlib.h>

#include<string.h>

class buffer;

class student

{

char age[5];

char usn[20];

char name[20];

char branch[10];

char sem[5];

public:

void input();

void output();

friend class buffer;

friend class primaryindexing;

friend class secondaryindexing;

};

class buffer

{

char b[70];

public:

void pack(student &s);


void unpack(student &s);

void Read(fstream& fs);

int Write(char* filename);

buffer();

};

class primaryindexing

{

char keys[30][2][20];

int size;

char *indexfilename;

char *recordfilename;

public:

void retrieveOffset(int i,int &offset);

primaryindexing(char *rfilename,char *ifilename,int &offset);

~primaryindexing();

void writeOffset(int &offset);

int Insert(student &s,int &offset);

void Delete(char * usn);

void Search(char *usn);

int find(char *usn);

};

class secondaryindexing

{

char keys[30][2][20];

int size;

char *indexfilename;

char *recordfilename;

public:


void Insert(student &s);

void Search(char *name,primaryindexing &p);

void Delete(char *key);

secondaryindexing(char *rfilename,char *ifilename);

~secondaryindexing();

};

secondaryindexing :: secondaryindexing(char *rfilename,char *ifilename)

{

indexfilename = ifilename;

recordfilename = rfilename;

fstream indexfile(indexfilename,ios::in);

char usn[20],name[20];

size = 0;

while(indexfile)

{

indexfile.getline(name,20,'|');

indexfile.getline(usn,20,'|');

if(indexfile.eof())

break;

strcpy(keys[size][0],name);

strcpy(keys[size][1],usn);

size++;

}

indexfile.close();

}

void secondaryindexing :: Insert(student& s)

{

int i = size-1;


while(i>=0 && strcmp(s.name,keys[i][0]) < 0)

{

strcpy(keys[i+1][0],keys[i][0]);


i--;

}

while(i>=0 && strcmp(s.name,keys[i][0]) == 0 && strcmp(s.usn,keys[i][1]) < 0)

{



i--;

}

i++;

strcpy(keys[i][0],s.name);

strcpy(keys[i][1],s.usn);

size++;

}

void secondaryindexing :: Search(char *name,primaryindexing &p)

{

int offset,pos;

student s;

buffer b;

fstream file(recordfilename,ios::in);

int flag = 0;

for(int i = 0; i < size; i++)

{

if(strcmp(name,keys[i][0]) == 0)

{


pos = p.find(keys[i][1]);

if(pos!= -1)

{

p.retrieveOffset(pos,offset);

file.seekg(offset);

b.Read(file);

b.unpack(s);

cout<<"-------------"<<endl;

s.output();

cout<<"-------------"<<endl;

flag = 1;

}

}

}

if(!flag)

cout<<" The Record(s) with the given name was not found "<<endl;

}

void secondaryindexing :: Delete(char *key)

{

for(int i = 0; i < size; i++)

if(strcmp(key,keys[i][1]) == 0)

sprintf(keys[i][1],"%d",-1);

}

secondaryindexing :: ~secondaryindexing()

{

fstream indexfile(indexfilename,ios::out|ios :: trunc);

for(int i = 0; i < size;i++)

{


indexfile.write(keys[i][0],strlen(keys[i][0]));

indexfile<<'|';


indexfile<<'|';

}

Indexfile.close();

}

int primaryindexing :: find(char *usn)

{

int first = 0, last = size-1;

int mid,temp;

while(first <= last)

{

mid = (first+last)/2;

temp = strcmp(keys[mid][0],usn);

if(temp == 0)

return mid;

else if(temp > 0)

last = mid-1;

else

first = mid+1;

}

return -1;

}

int primaryindexing :: Insert(student &s,int &offset)

{

int pos = find(s.usn);

if( pos != -1)


{

cout<<" The Record With the Given Key Already Exists "<<endl;

return 0;

}

buffer b;

b.pack(s);

int add = b.Write(recordfilename);

int i = size-1;

while(i >= 0 && strcmp(s.usn,keys[i][0]) < 0)

{



i--;

}

i++;

char offstr[20];

sprintf(offstr,"%d",offset);

strcpy(keys[i][0],s.usn);

strcpy(keys[i][1],offstr);

size++;

offset = offset + add;

return 1;

}

void primaryindexing :: Delete(char *usn)

{

int i = find(usn);

if(i == -1)

{


cout<<"No Such Record Exists "<<endl;

return;

}

if( i == size-1)

{

cout<<"Record With the Given usn Was successfully deleted!!!"<<endl;

size--;

return;

}

for(; i < size; i++)

{

strcpy(keys[i][0],keys[i+1][0]);

strcpy(keys[i][1],keys[i+1][1]);

}

size--;

cout<<"Record With the Given usn Was successfully deleted!!!"<<endl;

}

void primaryindexing :: Search(char *usn)

{

int i = find(usn);

if(i == -1)

{

cout<<"No Such Record Exists "<<endl;

return;

}

fstream fs(recordfilename,ios::in|ios::out);

int offset;

student s;


retrieveOffset(i,offset);

fs.seekg(offset);

buffer b;

b.Read(fs);

b.unpack(s);

s.output();

fs.close();

}

primaryindexing :: primaryindexing(char *rfilename,char* ifilename,int &offset)

{

indexfilename = ifilename;

recordfilename = rfilename;

fstream indexfile(indexfilename,ios::in);

char usn[20],offstr[20];

size = 0;

if(!indexfile)

{

offset = 0;

return;

}

indexfile.read((char*)&offset,sizeof(offset));

while(indexfile)

{

indexfile.getline(usn,20,'|');

indexfile.getline(offstr,20,'|');

if(indexfile.eof())

break;

strcpy(keys[size][0],usn);


strcpy(keys[size][1],offstr);

cout<<usn<<" "<<offstr<<endl;

size++;

}

indexfile.close();

}

void primaryindexing :: retrieveOffset(int i,int& offset)

{

char offstr[20];

strcpy(offstr,keys[i][1]);

offset = atoi(offstr);

}

void primaryindexing :: writeOffset(int &offset)

{

fstream indexfile(indexfilename,ios::out|ios :: trunc);

indexfile.write((char*)&offset,sizeof(offset));

indexfile.close();

}

primaryindexing :: ~primaryindexing()

{

fstream indexfile(indexfilename,ios::out|ios :: app);

for(int i = 0; i < size;i++)

{


indexfile<<'|';


indexfile<<'|';

}


indexfile.close();

}

void student :: input()

{

cout<<"Enter The Usn"<<endl;

cin>>usn;

cout<<"Enter The Name"<<endl;

cin>>name;

cout<<"Enter The Branch"<<endl;

cin>>branch;

cout<<"Enter The Semester"<<endl;

cin>>sem;

}

void student :: output()

{

cout<<"Usn:";

puts(usn);

cout<<"Name:";

puts(name);

cout<<"Branch:";

puts(branch);

cout<<"Semester:";

puts(sem);

}

buffer :: buffer()

{

for(int i = 0; i < 70; i++)

b[i] = '\0';


}

void buffer :: pack(student &s)

{

strcpy(b,s.usn);

strcat(b,"|");

strcat(b,s.name);

strcat(b,"|");

strcat(b,s.branch);

strcat(b,"|");

strcat(b,s.sem);

strcat(b,"|");

}

void buffer :: unpack(student &s)

{

char *p = b;

while(*p)

{

if(*p == '|')

*p = '\0';

p++;

}

p = b;

strcpy(s.usn,p);

p = p +strlen(p)+1;

strcpy(s.name,p);

p = p +strlen(p)+1;

strcpy(s.branch,p);

p = p +strlen(p)+1;


strcpy(s.sem,p);

}

int buffer :: Write(char *filename)

{

fstream datafile(filename,ios::out|ios::app);

datafile.write(b,sizeof(b));

datafile.close();

return sizeof(b);

}

void buffer :: Read(fstream& fs)

{

fs.read(b,sizeof(b));

}

int main()

{

int choice =1,flag;

int offset;

student s;

char recordfilename[] = "record.txt";

char pindexfilename[] = "pindex.txt";

char sindexfilename[] = "sindex.txt";

char key[20];

primaryindexing iobj(recordfilename,pindexfilename,offset);

secondaryindexing sobj(recordfilename,sindexfilename);

while(choice < 4)

{

cout<<"1.Add Record"<<endl;

cout<<"2.Delete Record"<<endl;


cout<<"3.Search Record"<<endl;

cout<<"4.Exit"<<endl;

cin>> choice;

switch(choice)

{

case 1: s.input();

flag = iobj.Insert(s,offset);

if(flag)

sobj.Insert(s);

break;

case 2: cout<<"Enter The Usn Of Record to be deleted"<<endl;

cin>>key;

iobj.Delete(key);

sobj.Delete(key);

break;

case 3: cout<<"Enter The Name Of Record(s) to be

Searched"<<endl;

cin>>key;

sobj.Search(key,iobj);

break;

}

}

iobj.writeOffset(offset);

return 0;

}


Output:

1: add record

2: delete record

3:search record

4:exit

1

Enter the USN

1bg09is002

Enter the name

Akshata

Enter the branch

Ise

Enter the semester

6

1: add record

2: delete record

3:search record

4:exit

1

Enter the USN

1bg09is087

Enter the name

sandeep

Enter the branch

Ise

Enter the semester

6

1: add record


2: delete record

3:search record

4:exit

3

Enter the name of record to be searched

Sandeep

----------------------------------

USN: 1bg09is087

Name: sandeep

Branch:ise

Sem:6

-----------------------------------

1: add record

2: delete record

3:search record

4:exit

3


Anitha

Record with the given name was not found

1: add record

2: delete record

3:search record

4:exit

2

Enter your usn of record to be deleted

1bg09is087

Record with given usn was successfully deleted


1: add record

2: delete record

3:search record

4:exit

3


Sandeep

Record with given name was not found

1: add record

2: delete record

3:search record

4:exit

4

Output from files before deletion

Record.txt

1bg09is002|akshata|ise|6

1bg09is087|sandeep|ise|6

Pindex.txt

1bg09is002|0|1bg09is087|70

Sindex.txt

Akshata|1bg09is002|sandeep|1bg09is087

Output from files after deletion

Record.txt

1bg09is002|akshata|ise|6

Pindex.txt

1bg09is002|0

Sindex.txt

Akshata|1bg09is002


Program 7

Write a C++ program to read two lists of names and then match the names in the two lists using Cosequential Match based on a single loop.


#include<stdio.h>

#include<fstream.h>

#include<stdlib.h>

#include<string.h>

#include<process.h>

#include<conio.h>

class coseq

{

char list1[100][20],list2[100][20];

int n1,n2;

public: void load();

void seq_sort();

void match();

};

fstream f1,f2,of;

void coseq :: load()

{

n1=n2=-1;

while(!f1.eof())

f1.getline(list1[++n1],20,'\n');

while(!f2.eof())

f2.getline(list2[++n2],20,'\n');

}

void coseq :: seq_sort()


{

char temp[30];

for(int i=0;i<n1;i++)

{

for(int j=i+1;j<n2;j++)

{

if(strcmp(list1[i],list1[j])>0)

{

strcpy(temp,list1[i]);

strcpy(list1[i],list1[j]);

strcpy(list1[j],temp);

}

}

}

for(i=0;i<n2;i++)

{

for(int j=i+1;j<n2;j++)

{

if(strcmp(list2[i],list2[j])>0)

{

strcpy(temp,list2[j]);

strcpy(list2[i],list2[j]);

strcpy(list2[j],temp);

}

}

}

}

void coseq :: match()


{

int i=0,j=0;

while((i<=n1)&&(j<=n2))

{

if(strcmp(list1[i],list2[j])==0)

{

cout<<list1[i]<<endl;

of<<list1[i]<<endl;

i++;

j++;

continue;

}

else if(strcmp(list1[i],list2[j])>0)

j++;

else

i++;

}

}

void main()

{

clrscr();

coseq cq;

f1.open("file1.txt",ios::in);


if(!f1||!f2)

{

cout<<"\n ERROR file dont exist";

getch();


exit(1);

}

cq.load();f1.close();f2.close();



of.open("file3.txt",ios::out);

cq.seq_sort(); cq.match();

f1.close();

f2.close();

of.close();

getch();

}

Output:

Sunil

Input file “file1.txt” contains list1

sunil

jyothi

pradeep

Input file “file2.txt” contains list2

suma

avinash

sunil

kruthi

Output file “file3.txt” contains matched names

sunil


Progrm 8

Write a C++ program to read k Lists of names and merge them using kway merge algorithm with k = 8.

#include<stdio.h>

#include<conio.h>


#include<string.h>

#include<fstream.h>

#include<stdlib.h>

fstream file[8];

char fname[8][8]={"1.txt","2.txt","3.txt","4.txt","5.txt","6.txt","7.txt","8.txt"};

int no;

class record

{

public:char name[20],usn[20];

}rec[20];

void merge(char* file1,char* file2,char* filename)

{

int k=0;

record rec[20];

fstream f1,f2;

f1.open(file1,ios::in);

f2.open(file2,ios::in);

while(!f1.eof())

{

f1.getline(rec[k].name,20,'|');

f1.getline(rec[k++].usn,20,'\n');


}

while(!f2.eof())

{

f2.getline(rec[k].name,20,'|');

f2.getline(rec[k++].usn,20,'\n');

}

int t,y;

record temp;

for(t=0;t<k-2;t++)

for(y=0;y<k-t-2;y++)

if(strcmp(rec[y].name,rec[y+1].name)>0)

{

temp=rec[y];

rec[y]=rec[y+1];

rec[y+1]=temp;

}

fstream temp1;

temp1.open(filename,ios::out);

for(t=1;t<k-1;t++)

temp1<<rec[t].name<<"|"<<rec[t].usn<<"\n";

f1.close();

f2.close();

temp1.close();

return;

}

void kwaymerge()

{

char filename[7][20]={"11.txt","22.txt","33.txt", "44.txt"," 111.txt","222.txt" ,


"1111.txt"};

int k=0,i;

for(i=0;i<8;i+=2)

merge(fname[i],fname[i+1],filename[k++]);

k=4;

for(i=0;i<4;i+=2)

merge(filename[i],filename[i+1],filename[k++]);

merge(filename[4],filename[5],filename[6]);

return;

}

void main()

{

char name[20],usn[20],branch[20];

int i;

clrscr();

cout<<"enter the no of records\n";

cin>>no;

cout<<"enter the details of students";

for(i=0;i<8;i++)

file[i].open(fname[i],ios::out);

for(i=0;i<no;i++)

{

cout<<"name:";

cin>>rec[i].name;

cout<<"usn:";

cin>>rec[i].usn;

file[i%8]<<rec[i].name<<"|"<<rec[i].usn<<"\n";

}


for(i=0;i<8;i++)

file[i].close();

kwaymerge();

fstream result;

result.open("1111.txt",ios::in);

cout<<"sorted order\n";

for(i=0;i<no;i++)

{

result.getline(name,20,'|');

result.getline(usn,20,'\n');

cout<<"\nname="<<name<<"\n"<<"usn="<<usn<<"\n";

} getch();

}

Output:

Enter the no of records 10

Enter the details

Name: jyothi

Usn: 1

Name: nidhi

Usn: 2

Name: ashik

Usn: 3

Name: suraj

Usn: 4

Name: kruthi

Usn: 5

Name: harsha

Usn: 6


Name: shruthi

Usn: 7

Name: teju

Usn: 8

Name: seema

Usn: 9

Name: kavitha

Usn: 2

Sorted records are:

Name: ashik

Usn: 3

Name: harsha

Usn: 6

Name: jyothi

Usn: 1

Name: kavitha

Usn: 2

Name: kruthi

Usn: 5

Name: nidhi

Usn: 2

Name: seema

Usn: 9

Name: shruthi

Usn: 7

Name: suraj

Usn: 4

Name: teju


Usn: 8


Program 9

Write a C++ program to implement B-Tree for a given set of integers and its operations insert ( ) and search ( ). Display the tree.


#include<stdio.h>

#include<fstream.h>

#include<stdlib.h>

#include<string.h>

class node

{

public:

int a[4];

node * next[4];

node * parent;

int size;

node();

};

node :: node()

{

for(int i = 0; i < 4; i++)

next[i] = NULL;

parent = NULL;

size = 0;

}

class btree

{

node * root;


publicc:

node* findLeaf(int key,int &level);

void updateKey(node *p,node *c,int newKey);

void search(int key);

void insert(int key);

void insertIntoNode(node *n,int key,node *address);

void promote(node *n,int key,node *address);

node* split(node *n);

void traverse(node *ptr);

btree();

};

void btree :: traverse(node *ptr)

{

if(ptr == NULL)

return;

for(int i = 0; i < ptr->size; i++)

cout<<ptr->a[i]<<" ";

cout<<endl;

for(i = 0; i < ptr->size;i++)

traverse(ptr->next[i]);

}

btree :: btree()

{

root = NULL;

}

node* btree :: findLeaf(int key,int &level)

{

node *ptr = root;


node *prevptr = NULL;

level = 0;

int i;

while(ptr)

{

i = 0;

level++;

while(i < ptr -> size-1 && key > ptr -> a[i])

i++;

prevptr = ptr;

ptr = ptr -> next[i];

}

return prevptr;

}

node* btree :: split(node *n)

{

int midpoint = (n -> size+1)/2;

int newsize = n->size - midpoint;

node *newptr = new node;

node *child;

newptr->parent = n -> parent;

int i;

for(i = 0; i < midpoint; i++)

{

newptr->a[i] = n->a[i];

newptr ->next[i] = n->next[i];

n->a[i] = n->a[i+midpoint];

n->next[i] = n->next[i+midpoint];


}

n->size = midpoint;

newptr -> size = newsize;

for( i = 0; i < n->size; i++)

{

child = n->next[i];

if(child!= NULL)

child -> parent = n;

}

for( i = 0; i < newptr -> size; i++)

{

child = newptr -> next[i];

if(child!= NULL)

child -> parent = newptr;

}

return newptr;

}

void btree :: updateKey(node *parent,node *child,int newkey)

{

if( parent == NULL)

return;

if(parent->size == 0)

return;

int oldkey = child->a[child->size-2];

for(int i = 0; i < parent->size;i++)

if(parent->a[i] == oldkey)

{

parent->a[i] = newkey;


parent->next[i] = child;

}

}

void btree :: insertIntoNode(node *n,int key,node *address)

{

int i;

if( n == NULL)

return;

for(i = 0; i < n->size; i++)

if(n->a[i] == key)

return;

i = n->size-1;

while(i >= 0 && n -> a[i] > key)

{

n->a[i+1] = n->a[i];

n->next[i+1] = n->next[i];

i--;

}i++;

n->a[i] = key;

n->next[i] = address;

n->size++;

if( i == n->size-1)

updateKey(n->parent,n,key);

}

void btree :: promote(node *n,int key,node *address)

{

if( n == NULL)

return;


if(n -> size < 4)

{

insertIntoNode(n,key,address);

return;

}

if( n == root)

{

root = new node;

n->parent = root;

}

node *newptr = split(n);

node *t;

if(key < n->a[0])

t = newptr;

else

t = n;

insertIntoNode(t,key,address);

promote(n->parent,n->a[n->size-1],n);

promote(newptr->parent,newptr->a[newptr->size-1],newptr);

}

void btree :: insert(int key)

{

if( root == NULL)

{

root = new node;

root->a[root->size] = key;

root->size++;

return;


}

int level;

node *leaf = findLeaf(key,level);

int i;

for(i = 0; i < leaf->size; i++)

if(leaf -> a[i] == key)

{

cout<<"The Key to be inserted already exists"<<endl;

return;

}

promote(leaf,key,NULL);

cout<<"---------------\n";

traverse(root);

cout<<"----------------\n";

}

void btree :: search(int key)

{

if(root == NULL)

{

cout<<"The tree Does not exist"<<endl;

return;

}

int level;


int flag = 0;

for(int i = 0; i < leaf ->size; i++)

if(leaf->a[i] == key)

{


flag = 1;

cout<<"The Key "<<key<<" Exists in the B-Tree at the

level"<<level<<endl;

}

if(!flag)

cout<<"The Key Searched for was not found"<<endl;

}

int main()

{

btree b;

int choice = 1,key;

while(choice <=2)

{

cout<<"1.Insert a Key\n";

cout<<"2.Search a key\n";

cout<<"3.Exit\n";

cin>>choice;

switch(choice)

{

case 1: cout<<"Enter The Key to be inserted in B-Tree\n";

cin>>key;

b.insert(key);

break;

case 2: cout<<"Enter The key to be searched\n";

cin>>key;

b.search(key);

break;

}


}

return 0;

}

Output

1.Insert a Key

2.Search a key

3.Exit

1

Enter The Key to be inserted in B-Tree

5

1.Insert a Key

2.Search a key

3.Exit

1


8

---------------

5 8

----------------

1.Insert a Key

2.Search a key

3.Exit

1


4

---------------

4 5 8

----------------


1.Insert a Key

2.Search a key

3.Exit

1.Insert a Key

2.Search a key

3.Exit

1


7

---------------

4 5 7 8

----------------

1.Insert a Key

2.Search a key

3.Exit

1


11

---------------

5 11

4 5

7 8 11

----------------

1.Insert a Key

2.Search a key

3.Exit

2


Enter the key to be searched

11

Key found at level 2

1.Insert a Key

2.Search a key

3.Exit

3


Program 10

Write a C++ program to implement B+ tree for a given set of integers and its operations insert ( ), and search ( ). Display the tree.


#include<stdio.h>

#include<fstream.h>

#include<stdlib.h>

#include<string.h>

class node

{

public:

int a[4];

node * next[4];

node * parent;

int size;

node();

};

class linkleaf

{

public:

node * data;

linkleaf *next;

linkleaf();

};

linkleaf :: linkleaf()

{

next = NULL;


}

node :: node()

{

for(int i = 0; i < 4; i++)

next[i] = NULL;

parent = NULL;

size = 0;

}

class btree

{

node * root;

linkleaf *head;

int flag;

public:

node* findLeaf(int key,int &level);

void updateKey(node *p,node *c,int newKey);

void search(int key);

void insert(int key);

void insertIntoNode(node *n,int key,node *address);

void promote(node *n,int key,node *address);

node* split(node *n);

void traverse(node *ptr);

void connectLeaf(node *n,node *newptr);

void traverseleaf();

btree();

};

void btree :: traverseleaf()

{


linkleaf * ptr = head;

int i;

while(ptr)

{

for(i = 0; i < ptr -> data -> size; i++)

cout<<ptr -> data -> a[i]<<" ";

cout<<endl;

ptr = ptr ->next;

}

}

void btree :: connectLeaf(node *n,node *newptr)

{

linkleaf *ptr = head,*prevptr = NULL,*p;

while(ptr)

{

if(ptr-> data == n)

break;

prevptr = ptr;

ptr = ptr ->next;

}

if( ptr == NULL)

{

cout<<"Unexpected Error!!";

exit(0);

}

if( ptr == head)

{


p = new linkleaf;

p -> next = head;

head = p;

p->data = newptr;

}

else

{

p = new linkleaf;

p-> next = ptr;

prevptr -> next = p;

p->data = newptr;

}

}

void btree :: traverse(node *ptr)

{

if(ptr == NULL)

return;

for(int i = 0; i < ptr->size; i++)

cout<<ptr->a[i]<<" ";

cout<<endl;

for(int i = 0; i < ptr->size;i++)

traverse(ptr->next[i]);

}

btree :: btree()

{

root = NULL;

head = NULL;

}


node* btree :: findLeaf(int key,int &level)

{

node *ptr = root;

node *prevptr = NULL;

level = 0;

int i;

while(ptr)

{

i = 0;

level++;

while(i < ptr -> size-1 && key > ptr -> a[i])

i++;

prevptr = ptr;

ptr = ptr -> next[i];

}

return prevptr;

}

node* btree :: split(node *n)

{

int midpoint = (n -> size+1)/2;

int newsize = n->size - midpoint;

node *newptr = new node;

node *child;

newptr->parent = n -> parent;

int i;

for(i = 0; i < midpoint; i++)

{

newptr->a[i] = n->a[i];


newptr ->next[i] = n->next[i];

n->a[i] = n->a[i+midpoint];

n->next[i] = n->next[i+midpoint];

}

n->size = midpoint;

newptr -> size = newsize;

for( i = 0; i < n->size; i++)

{

child = n->next[i];

if(child!= NULL)

child -> parent = n;

}

for( i = 0; i < newptr -> size; i++)

{

child = newptr -> next[i];

if(child!= NULL)

child -> parent = newptr;

}

return newptr;

}

void btree :: updateKey(node *parent,node *child,int newkey)

{

if( parent == NULL)

return;

if(parent->size == 0)

return;

int oldkey = child->a[child->size-2];

for(int i = 0; i < parent->size;i++)


if(parent->a[i] == oldkey)

{

parent->a[i] = newkey;

parent->next[i] = child;

}

}

void btree :: insertIntoNode(node *n,int key,node *address)

{

int i;

if( n == NULL)

return;

for(i = 0; i < n->size; i++)

if(n->a[i] == key)

return;

i = n->size-1;

while(i >= 0 && n -> a[i] > key)

{

n->a[i+1] = n->a[i];

n->next[i+1] = n->next[i];

i--;

}

i++;

n->a[i] = key;

n->next[i] = address;

n->size++;

if( i == n->size-1)

updateKey(n->parent,n,key);

}


void btree :: promote(node *n,int key,node *address)

{

if( n == NULL)

return;

if(n -> size < 4)

{

insertIntoNode(n,key,address);

return;

}

if( n == root)

{

root = new node;

n->parent = root;

}

node *newptr = split(n);

node *t;

if(key < n->a[0])

t = newptr;

else

t = n;

insertIntoNode(t,key,address);

if(!flag)

{

connectLeaf(n,newptr);flag = 1;}

promote(n->parent,n->a[n->size-1],n);

promote(newptr->parent,newptr->a[newptr->size-1],newptr);

}


void btree :: insert(int key)

{

flag = 0;

if( root == NULL)

{

root = new node;

root->a[root->size] = key;

root->size++;

head = new linkleaf;

head -> data = root;

return;

}

int level;


int i;

for(i = 0; i < leaf->size; i++)

if(leaf -> a[i] == key)

{

cout<<"The Key to be inserted already exists"<<endl;

return;

}

promote(leaf,key,NULL);

cout<<"---------------\n";

traverse(root);

cout<<"----------------\n";

}

void btree :: search(int key)

{


if(root == NULL)

{

cout<<"The tree Does not exist"<<endl;

return;

}

int level;


int flag = 0;

for(int i = 0; i < leaf ->size; i++)

if(leaf->a[i] == key)

{

flag = 1;

cout<<"The Key "<<key<<" Exists in the B-Tree at the level" <<

level<< endl;

}

if(!flag)

cout<<"The Key Searched for was not found"<<endl;

}

int main()

{

btree b;

int choice = 1,key;

while(choice <=3)

{

cout<<"1.Insert a Key\n";

cout<<"2.Search a key\n";

cout<<"3.Traverse Leaf\n";

cout<<"4.Exit\n";


cin>>choice;

switch(choice)

{

case 1: cout<<"Enter The Key to be inserted in B-Tree\n";

cin>>key;

b.insert(key);

break;

case 2: cout<<"Enter The key to be searched\n";

cin>>key;

b.search(key);

break;

case 3: b. traverseleaf();

break;

}

}

return 0;

}

Output

1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

1

Enter The Key to be inserted in B+Tree

5

1.Insert a Key

2.Search a key

3.traverse tree


4.Exit

1

Enter The Key to be inserted in B+Tree

8

---------------

5 8

----------------

1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

1


4

---------------

4 5 8

----------------

1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

1


7

---------------

4 5 7 8

----------------

1.Insert a Key


2.Search a key

3.traverse tree

4.Exit

1


11

---------------

5 11

4 5

7 8 11

----------------

1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

2

Enter the key to be searched

11

Key found at level 2

1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

3

------------------------

4 5

7 8 11

------------------------


1.Insert a Key

2.Search a key

3.traverse tree

4.Exit

4


Program 11

Write a C++ program to store and retrieve student data from file using hashing. Use any collision resolution technique.

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

#include<conio.h>

#include<fstream.h>


//Record specification

class node

{

public: char name[15],usn[15];

node *link;

};

node *h[29]; //Array of record pointers equal to size of hash keys – 29

void insert()

{

char name[15], usn[15], buffer[50];

fstream out;

out.open("student.txt",ios::app); //opening student.txt in append mode

if(!out)

{

cout<<"\nUnable to open the file in append mode";

getch();

return;

}


cout<<"\nEnter the name = "; cin>>name;

cout<<"\n Enter the usn = "; cin>>usn;

strcpy(buffer,name); //Packing the record onto the file using ‘|’ as a delimiter

strcat(buffer,"|");

strcat(buffer,usn);

strcat(buffer,"\n"); // \n delimiter for the record

out<<buffer; // appending the packed record onto the file

out.close();

}

//Insert record into the hash table

void hash_insert(char name1[], char usn1[], int hash_key)

{

node *p,*prev,*curr;

p = new node; //dynamically allocate space using ‘new’

strcpy(p->name,name1);

strcpy(p->usn,usn1);

p->link=NULL;

prev=NULL;

curr=h[hash_key];

if(curr==NULL) //getting the hash pointer location Case: No collision

{

h[hash_key]=p;

return;

}

while(curr!=NULL) // Case : On collision – Insert at rear end

{

prev=curr;

curr=curr->link;


}

prev->link=p;

}

void retrive()

{

fstream in;

char name[15],usn[15];

int j,count;

node *curr;

in.open("student.txt",ios::in); // open the record file in input mode

if(!in)

{

cout<<"\n Unable to open the file in input mode";

getch();

exit(0);

}

while(!in.eof())

{

in.getline(name,15,'|'); //unpacking the record

in.getline(usn,15,'\n');

count=0;

for(j=0; j<strlen(usn); j++) //Calculate sum of ascii values of USN

{

count=count+usn[j];

}

count=count%29; //Hash Key = ASCII count% 29

hash_insert(name,usn,count);

}


cout<<"\n Enter the usn = "; cin>>usn;

count=0;

for(j=0; j<strlen(usn); j++) // Calculating Hash Key

count=count+usn[j];

count=count%29;

curr=h[count];

if(curr == NULL)

{

cout<<"\nRecord not found";

getch();

return;

}

do

{

if(strcmp(curr->usn,usn)==0) //When the record is found, retrieve

{

cout<<"\nRecord found : "<<curr->usn<<" "<<curr->name;

getch();

return;

}

else

{

curr=curr->link;

}

}while(curr!=NULL); //Search till end of list

if(curr==NULL) //End of list reached with no record found

{

cout<<"\nRecord not found";


getch();

return;

}

}

void main()

{

int choice;

clrscr();

fstream out;

out.open("student.txt",ios::out);

if(!out)

{

cout<<"\nUnable to open the file in out mode";

getch();

exit(0);

}

for(;;)

{

cout<<"\n1:insert\n 2: retrive \n3:exit \nEnter the choice \n";

cin>>choice;

switch(choice)

{

case 1: insert();

break;

case 2: retrive();

break;

case 3: exit(0);

default: cout<<"\nInvalid option";


}

}

}

Output:

1: insert

2: retrieve

3: exit

Enter your choice

1

Enter name= sanjay

Enter usn=1bg09is056

1: insert

2: retrieve

3: exit

Enter your choice

1

Enter name= ashish


1: insert

2: retrieve

3: exit

Enter your choice

1

Enter name= shreya


1: insert

2: retrieve

3: exit


Enter your choice

2

Enter usn= 1bg09is056

Record found 1bg09is056 sanjay

1: insert

2: retrieve

3: exit

Enter your choice

3


Program 12

Write a C++ program to reclaim the free space resulting from the deletion of records using linked lists.

#include<stdio.h>


#include<conio.h>

#include<string.h>

#include<stdlib.h>

#include<fstream.h>

class node

{

public:char name[20],usn[20];

node *link;

};

node *first=NULL;

void writefile()

{

fstream out;

node *p;

char buffer[500];

out.open("a1.txt",ios::out);

if(!out)

{


getch();

exit(0);

}


p=first;

while(p!=NULL)

{

strcpy(buffer,p->name);

strcat(buffer,"|");

strcat(buffer,p->usn);

strcat(buffer,"\n");

out<<buffer;

p=p->link;

}

}

void display()

{

node *p;

if(first==NULL)

{

cout<<"the list is empty\n";

return;

//getch();

//exit(0);

}

p=first;

while(p!=NULL)

{

cout<<p->name<<" "<<p->usn<<"->";

p=p->link;

}

}


void insert()

{

node *p,*q;

char name[20],usn[20];

cout<<"name=";

cin>>name;

cout<<"usn=";

cin>>usn;

p=new node;

strcpy(p->name,name);

strcpy(p->usn,usn);

p->link=NULL;

if(first==NULL)

{

first=p;

writefile();

display();

return;

}

for(q=first;q->link!=NULL;q=q->link);

q->link=p;

writefile();

display();

return;

}

void del1()

{

char usn[15];


node *prev,*curr,*del;

//char usn;

//int del;

if(first==NULL)

{

cout<<"list is empty\n";

return;

//getch();

//exit(0);

}

cout<<"enter the usn u want to delete\n";

cin>>usn;

if(strcmp(first->usn,usn)==0)

{

del=first;

delete del;

first=first->link;

writefile();

display();

return;

}

prev=NULL;

curr=first;

while((strcmp(curr->usn,usn)!=0)&&(curr!=NULL))

{

prev=curr;

curr=curr->link;

}


if(curr==NULL)

{

cout<<"the rec with the usn "<<usn<<"did not find";

getch();

exit(0);

}

prev->link=curr->link;

writefile();

display();

}

void main()

{

int ch;

clrscr();

for(;;)

{

cout<<"1:insert\n2:delete\n3:quit";

cout<<"enter your choice\n";

cin>>ch;

switch(ch)

{

case 1:insert();

break;

case 2:del1();

break;

case 3:exit(0);

break;

default:"invalid choice\n";


break;

}

}

}

Output:

1: insert

2. delete

3. exit

Enter your choice

1

Name=menatha

Usn=1bg09is048

Menatha 1bg09is048

1: insert

2. delete

3. exit

Enter your choice

1

Name=subash

Usn=1bg09is067

Menatha 1bg09is048 subash 1bg09is067

1: insert

2. delete

3. exit

Enter your choice

1

Name=ayush

Usn=1bg09is005


Menatha 1bg09is048 subash 1bg09is067 ayush 1bg09is005

1: insert

2. delete

3. exit

Enter your choice

2

Enter the usn you want to delete

1bg09is048

subash 1bg09is067 ayush 1bg09is005

1: insert

2. delete

3. exit

Enter your choice

1

Name=Samarth

Usn=1bg09is063

subash 1bg09is067 ayush 1bg09is005 Samarth 1bg09is063

1: insert

2. delete

3. exit

Enter your choice

3


Documents

BNMIT file structure lab manual