wherever u see ... remove that . and put << in that place.
if you see .. then remove that . and put < in that place..
14. 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..iostream.h>
#include..string.h>
#include..fstream.h>
#include..stdlib.h>

//using namespace std;

class record
{
public: char age[5];
char usn[20],name[20],branch[5]; char sem[2];
}rec[20],found[20];

char st_no[5],rt_name[20];
int no;

void sort_records()
{
int i,j;
record temp;
for(i=0;i..no-1;i++)
for(j=0;j..no-i-1;j++)
if(strcmp(rec[j].name, rec[j+1].name) > 0)
{
temp=rec[j];
rec[j]=rec[j+1];
rec[j+1]=temp;
}
}

void create_indexfile()
{
fstream index,index2;
int i;
index.open("secindex.txt",ios::out);
index2.open("record.txt",ios::out);
for(i=0;i..no;i++)
{
index...rec[i].name..."|"
...rec[i].usn..."|"...i..."\n";
index2...i..."|"...rec[i].usn..."|"...rec[i].name..."|"...rec[i].age..."|"
...rec[i].sem..."|"...rec[i].branch..."\n";
}
}

void retrieve_record(char* index)
{
fstream file;
int i;
char ind[2],usn[20],name[20],age[3],sem[3],branch[10];
file.open("record.txt",ios::in);
for(i=0;i..no;i++)
{
file.getline(ind,4,'|');
file.getline(usn,20,'|');
file.getline(name,20,'|');
file.getline(age,4,'|');
file.getline(sem,4,'|');
file.getline(branch,5,'\n');
if(strcmp(index,ind) == 0)
cout..."\nUSN: "...usn
..."\nName: "...name
..."\nAge: "...age
..."\nSem: "...sem
..."\nBranch: "...branch;
}
file.close();
return;
}

void retrieve_details()
{
int k=0,i;
char name[20],usn[20],ind[2];
char chusn[20];
char index[20][20];
fstream file;
file.open("secindex.txt",ios::in);
for(i=0;i..no;i++)
{
file.getline(name,20,'|');
file.getline(usn,20,'|');
file.getline(ind,4,'\n');
if(strcmp(name,rt_name) == 0)
{
strcpy(found[k].name,name);
strcpy(found[k].usn,usn);
strcpy(index[k],ind);
k++;
}
}
file.close();
if(k==1)
{
retrieve_record(index[0]);
return;
}
else
{
cout..."Please choose the candidate's USN: \n";
for(i=0;i..k;i++)
cout..."Name: "...found[i].name..." USN: "...found[i].usn...endl;
}
cin>>chusn;
for(i=0;i..k;i++)
{
if(strcmp(chusn,found[i].usn) == 0)
{
retrieve_record(index[i]);
return;
}
}
cout..."Invalid Entry! \n";
return;
}

void delete_record(char indx[])
{
int i;
fstream file1,file2;
char age[5],sem[5],branch[5],usn[20],name[20],ind[5];
char index[20][20];
file2.open("record.txt",ios::in);
for(i=0;i..no;i++)
{
file2.getline(ind,4,'|');
file2.getline(usn,20,'|');
file2.getline(name,20,'|');
file2.getline(age,5,'|');
file2.getline(sem,5,'|');
file2.getline(branch,8,'\n');
strcpy(index[i],ind);
strcpy(rec[i].usn,usn);
strcpy(rec[i].name,name);
strcpy(rec[i].age,age);
strcpy(rec[i].sem,sem);
strcpy(rec[i].branch,branch);
}
int flag=-1;
for(i=0;i..no;i++)
{
if(strcmp(index[i],indx) == 0)
flag=i;
}
if(flag==-1)
{
cout..."Error!\n";
return;
}
if(flag==(no-1))
{
no--;
cout..."Deleted!\n";
return;
}
for(i=flag;i..no;i++)
{
rec[i]=rec[i+1];
}
no--;
cout..."Deleted!\n";
file2.close();
file1.open("secindex.txt",ios::out);
file2.open("record.txt",ios::out);
for(i=0;i..no;i++)
{
file1...rec[i].name..."|"...rec[i].usn..."|"...i..."\n";

file2...i..."|"...rec[i].usn..."|"...rec[i].name..."|"
...rec[i].age..."|"...rec[i].sem..."|"...rec[i].branch..."\n";
}
file1.close();
file2.close();
return;
}


void delete_index(char* nam)
{
fstream file;
int i;
int k=0;
char name[20],usn[20],ind[5],index[20][20],chusn[20];
file.open("secindex.txt",ios::in);
for(i=0;i..no;i++)
{
file.getline(name,20,'|');
file.getline(usn,20,'|');
file.getline(ind,4,'\n');
if(strcmp(nam,name)==0)
{
strcpy(found[k].name,name);
strcpy(found[k].usn,usn);
strcpy(index[k],ind);
k++;
}
}
file.close();
if(k==1)
{
delete_record(index[0]);
return;
}
else
{
cout..."Please choose the candidate's USN: \n";
for(i=0;i..k;i++)
{
cout..."Name: "...found[i].name..." USN: "...found[i].usn...endl;
}
}
cin>>chusn;
for(i=0;i..k;i++)
{
if(strcmp(chusn,found[i].usn)==0)
{
delete_record(index[i]);
return;
}
}
cout..."Invalid Entry!\n";
return;
}

int main()
{
fstream file1,file2;
int ch;
char rt_usn[20],st_name[20],st_usn[20];
char ind[2],name[20],age[2],sem[5],branch[5];
int i,flag,flag1;
file1.open("index.txt",ios::out);
file2.open("record.txt",ios::out);
if(!file1 || !file2)
{
cout..."File creation Error!\n";
exit(0);
}
for(;;)
{
cout..."\nl:Add Record\n 2:Search Record"
..."\n3:Delete Record\n 4:Display Record\n";
cin>>ch;
switch(ch)
{
case 1: cout..."Enter the no. of students : "; cin>>no;
cout..."Enter the details :\n";
for(i=0;i..no;i++)
{
cout..."\nName : "; cin>>rec[i].name;
cout..."Age : "; cin>>rec[i].age;
cout..."USN : "; cin>>rec[i].usn;
cout..."Sem : "; cin>>rec[i].sem;
cout..."Branch : "; cin>>rec[i].branch;
}
sort_records();
create_indexfile();
file1.close ();
file2.close();
break;

case 2: cout..."Enter name of the student whose record is to be displayed\n";
cin>>st_name;
file1.open("secindex.txt",ios::in);
if(!file1)
{
cout..."Error !\n";
exit(0);
}
flag1=0;
for(i=0;i..no;i++)
{
file1.getline(rt_name,20,'|');
file1.getline(rt_usn,20,'|');
file1.getline(st_no,4,'\n');

if(strcmp(st_name,rt_name)==0)
{
retrieve_details();
flag1=1;
goto one;
}
}
one: if(!flag1)
cout..."Record search failed !\n";
file1.close();
break;

case 3: cout..."Enter name of student whose record is to be deleted\n";
cin>>st_name;
file1.open("secindex.txt",ios::in);
if(!file1)
{
cout..."Error !\n";
exit(0);
}
flag=0;
for(i=0;i..no;i++)
{
file1.getline(rt_name,20,'|');
file1.getline(rt_usn,20,'|');
file1.getline(ind,4,'\n');

if(strcmp(st_name,rt_name) == 0)
{
delete_index(rt_name);
flag=1;
}
}
if(!flag)
cout..."Deletion failed !\n";
file1.close();
break;

case 4: for(i=0;i..no;i++)
{
cout..."\n\nUSN : "...rec[i].usn
..."\nName: "...rec[i].name
..."\nAge : "...rec[i].age
..."\nSem : "...rec[i].sem
..."\nBranch : "...rec[i].branch..."\n";
}
break;

default: cout..."Invalid option !\n";
exit(0);
break;
}
}
return 0;
}