this is k-way merge algorithm

1. #include<iostream>
#include<stdio.h>
#include<string.h>
#include<fstream>
#include<stdlib.h>
#include<iomanip>
//record specification
using namespace std;
fstream data,indx;
char pri[125][15]; // to hold primary keys
int ind[125],count=0;
void sort1();
class student
{
public :
char Regno[10], Name[25], Address[50], Sem[5], Branch[10],
College[15];
public:
void Insert();
void Delete();
void Search(char *a); /* To display individual record */
void Display();/* to display all records in file-- yet to
implement*/
// void Loadindx();
void Writeindx();
}s;
void student::Insert()
{
char Buffer[100],offset[10];
int pos, high = count;
data.open("stu.txt",ios::app);
data.seekg(0,ios::end);
pos=data.tellg(); // gets the address of that posn
cout<<"ENTER RECORD DETAILSn";
cout<<"RegNo : ";
cin>>s.Regno;
for(int low=0;low<=high;)
{
int mid = (low+high)/2;
int k = atoi(pri[mid]), m = atoi(s.Regno);
if(k == m)
{
cout<<setw(44)<<"DUPLICATE RECORD !!!";
return;
}
else if(m < k)
high = mid-1;
else if(m > k)
low = mid + 1;
} // to search for duplicate usn -- can avoid
cout<<"Name : "; cin>>s.Name;
cout<<"Address : "; cin>>s.Address;
cout<<"Sem : "; cin>>s.Sem;
cout<<"Branch : "; cin>>s.Branch;
cout<<"College : "; cin>>s.College;
sprintf(Buffer,"|%s|%s|%s|%s|%s|%s|
#",s.Regno,s.Name,s.Address,s.Sem,s.Branch,s.College);
data<<Buffer;

2. strcpy(pri[count],s.Regno);
ind[count]=pos;
count++;
cout<<count;
data.close();
s.Writeindx();
}
void student::Writeindx()
{
char buffer[100];
int i;
indx.open("inx.txt", ios::out);
sort1();
for(i=0;i<count;i++)
{
//itoa(ind[i],buffer,10);
sprintf(buffer, "%d", ind[i]);
indx<<"|"<<pri[i]<<"|"<<buffer<<"|"<<"#";
}
indx.close();
}
void sort1()
{
char temp[20];
int tempind,k,i,j,l;
for(i=0;i<count;i++)
{
for(j=i+1;j<count;j++)
{
k = atoi(pri[i]);
l = atoi(pri[j]);
if(k > l)
{
strcpy(temp,pri[i]);
strcpy(pri[i],pri[j]);
strcpy(pri[j],temp);
tempind=ind[j];
ind[j]=ind[i];
ind[i]=tempind;
}
}
}
}
void student::Search(char *reg)
{
int high = count,flag1=0;
char Buffer[100];
data.open("stu.txt",ios::in);
for(int low=0;low<=high;)
{
int mid = (low+high)/2;
int k = atoi(pri[mid]), m = atoi(reg);
if(k == m) // or else use strcmp()==0
{
flag1 = 1;
data.seekg(ind[mid],ios::beg);
data.getline(Buffer,100,'#');
sscanf(Buffer,"|%[^|]|%[^|]|%[^|]|%[^|]|%[^|]|%
[^|]#",s.Regno,s.Name,s.Address,s.Sem,s.Branch,s.College);
cout<<endl<<"RECORD DETAILS"<<endl;
cout<<endl<<"URN : "<<s.Regno;
cout<<endl<<"NAME : "<<s.Name;
cout<<endl<<"ADDRESS : "<<s.Address;
cout<<endl<<"SEMESTER : "<<s.Sem;

3. cout<<endl<<"BRANCH : "<<s.Branch;
cout<<endl<<"COLLEGE : "<<s.College<<"n";
data.close();
return; // or use break stmt here
}
else if(m < k)
high = mid-1;
else if(m > k)
low = mid + 1;
}
if(flag1==0)
cout<<endl<<"RECORD DOES NOT EXISTSn";
data.close();
}
void student::Delete()
{
char reg[20],Buffer[100],usn[15];
int high = count,flag=0;
cout<<endl<<"ENTER USN: ";
cin>>reg;
data.open("stu.txt",ios::in | ios::out);
for(int low=0;low<=high;)
{
int mid = (low+high)/2;
int k = atoi(pri[mid]), m = atoi(reg);
if(k == m)
{
flag=1;
data.seekg(ind[mid],ios::beg);
data.getline(Buffer,100,'#');
Buffer[0]='*';
pri[mid][0]='*';
data.seekg(ind[mid],ios::beg);
data<<Buffer;
cout<<endl<<"RECORD DELETED";
data.close();
s.Writeindx();
return;
}
else if(m < k)
high = mid-1;
else if(m > k)
low = mid + 1;
}
if(flag==0)
{
cout<<endl<<"RECORD NOT FOUND !!!";
}
data.close();
}
void student :: Display()
{
char Buffer[100];
data.open("stu.txt",ios::in);
char b[100];
while(!data.eof())
{
data.getline(Buffer,100,'#');
if(data.eof())

4. break;
if(Buffer[0]!='*')
{
sscanf(Buffer,"|%[^|]|%[^|]|%[^|]|%[^|]|%[^|]|%
[^|]#",s.Regno,s.Name,s.Address,s.Sem,s.Branch,s.College);
cout<<s.Regno<<" "<<s.Name<<" "<<s.Address<<" "<<s.Sem<<"
"<<s.Branch<<" "<<s.College<<endl;
}
else
continue;
}
data.close();
}
int main()
{
fstream f1,f2;
int choice;
char usn[20];
for(;;)
{
cout<<"n1.Add record n2.search record n
3.deleterecordn4.display recordn";
cin>>choice;
switch(choice)
{
case 1:s.Insert();
break;
case 2:cout<<endl<<"ENTER UsN: ";
cin>>usn;
s.Search(usn);
break;
case 3:s.Delete();
break;
case 4: s.Display();
break;
default: exit(0);
}
}
}