Hashing Program of Student Record

Implement direct access file using hashing (chaining without replacement) and perform following operations on it.

*Store data of students with telephone no and name in the structure using hashing function for telephone number and implement chaining with and
without replacement.*/

#include <iostream>
#include <string.h>
#define MAX 10
using namespace std;
class hashing           //ADT
{
            struct student
            {
                  long telephone_no; //telephone number
                  char name[MAX];    //name of the student
                  int chain;       //chain for chaining
            };
            struct student h[MAX];
      public:
            hashing();              //default constructor
            void Insert_wor();            //chaining without replacement
            void display();         //display
            void Insert_wr();       //chaining with replacement
            int hash(long);         //hash function
};

hashing::hashing()
{
      int i;
      for(i=0;i<MAX;i++)
         {
            h[i].telephone_no=-1;
            h[i].name[0]='\0';
            h[i].chain=-1;
         }
}

int hashing::hash(long tno)
{
      return(tno%MAX);
}

void hashing::Insert_wor()
{
      int index,index1,i;
      long tno;
      char nm[MAX],ch='y';
      while(ch=='y'||ch=='Y')
      {
            cout<<"\n Enter Telephone number and Name of the student: ";
            cin>>tno>>nm;
            cout<<nm;
            index=hash(tno);
            if(h[index].telephone_no==-1) //if empty slot
             {
                  //store the record
                  h[index].telephone_no=tno;
                  strcpy(h[index].name,nm);
             }
            else
             {
                  while(h[index].chain!=-1)
                        index=h[index].chain;
                  index1=index;
                  //apply linear probing technique
                  do
                  {
                              index=(index+1)%MAX;
                  }while((index!=index1) && (h[index].telephone_no!=-1));
                  if(index==index1)
                        cout<<"\nOverflow";
                  else
                          {
                              h[index].telephone_no=tno;
                              strcpy(h[index].name,nm);
                              h[index1].chain=index;
                         }
             }
             display();
             cout<<"\n Do you wanna enter 1 more record? (y/n)?";
             cin>>ch;
      }
}

void hashing::Insert_wr()
{
      int index,index1,index2,i,f=0;
      long tno;
      student s;
      char nm[MAX],nm1[MAX],ch='y';
      while(ch=='y'||ch=='Y')
      {
            cout<<"\n Enter Telephone number and Name of the student: ";
            cin>>tno>>nm;
            cout<<nm;

            index=hash(tno);

            if(h[index].telephone_no==-1) //if empty slot
             {
                  //store the record
                  h[index].telephone_no=tno;
                  strcpy(h[index].name,nm);
             }
            else
             {

                  //1. for synonym
                  if(hash(h[index].telephone_no)==index)
                  {
                      //traverse chain
                      while(h[index].chain!=-1)
                            index=h[index].chain;
                      // Linear Probing
                      index1=index;
                      do
                      {
                              index=(index+1)%MAX;
                      }while((index!=index1) && (h[index].telephone_no!=-1));

                  if(index==index1)
                        cout<<"\nOverflow";
                  else
                            {
                                  h[index].telephone_no=tno;
                              strcpy(h[index].name,nm);
                              h[index1].chain=index;

                         }

                  }

                  //Not a synonym
                  else if(hash(h[index].telephone_no)!=index)
                  {
                          s.telephone_no=h[index].telephone_no;
                        strcpy(s.name,h[index].name);
                        s.chain=h[index].chain;

                          h[index].telephone_no=tno;
                          strcpy(h[index].name,nm);
                          h[index].chain=-1;


                      // Linear Probing
                      index1=index;
                      do
                      {
                              index=(index+1)%MAX;
                      }while((index!=index1) && (h[index].telephone_no!=-1));

                      if(index==index1)
                            cout<<"\nOverflow";
                      else
                            {
                                  h[index].telephone_no=s.telephone_no;
                              strcpy(h[index].name,s.name);
                              h[index].chain=s.chain;

                              index2=0;
                                  while(h[index2].chain!=index1)
                                      index2++;
                                  h[index2].chain=index;

                          }

                  }

             }
             display();
             cout<<"\n Do you wanna enter 1 more record? (y/n)?";
             cin>>ch;
      }
}

void hashing::display()
{
      cout<<"\nIndex\tTelephone no\tName\tChain\n------------------------------------------------------------------------\n";
      for(int i=0;i<MAX;i++)
            cout<<i<<"\t"<<h[i].telephone_no<<"\t"<<h[i].name<<"\t"<<h[i].chain<<endl;
}

int main()
{
      hashing obj;
      int ch=1;
      while(ch)
      {
            cout<<"\nMenu\n1.Chaining without replacement\n2.Chaining with replacement\n3.Exit\nEnter your choice:";
            cin>>ch;
            switch(ch)
            {

                  case 1:
                        obj.Insert_wor();
                        break;
                  case 2:
                        obj.Insert_wr();
                        break;
                  case 3:
                        break;
                  default:
                        cout<<"\nWrong choice!!!";
            }
      }
      return 0;
}