C Program to implement Hashing using Linear and Quadratic Probing

/* HASHING - LINEAR AND QUADRATIC PROBING */

#include <stdio.h>
#include <conio.h>
int tsize;

int hasht(int key)
{
 int i ;
 i = key%tsize ;
 return i;
}

//-------LINEAR PROBING-------
int rehashl(int key)
{
 int i ;
 i = (key+1)%tsize ;
 return i ;
}

//-------QUADRATIC PROBING-------
int rehashq(int key, int j)
{
 int i ;
 i = (key+(j*j))%tsize ;
 return i ;
}

void main()
{
    int key,arr[20],hash[20],i,n,s,op,j,k ;
    clrscr() ;
    printf ("Enter the size of the hash table:  ");
    scanf ("%d",&tsize);

    printf ("\nEnter the number of elements: ");
    scanf ("%d",&n);

    for (i=0;i<tsize;i++)
 hash[i]=-1 ;

    printf ("Enter Elements: ");
    for (i=0;i<n;i++)
    {
 scanf("%d",&arr[i]);
    }

    do
    {
 printf("\n\n1.Linear Probing\n2.Quadratic Probing \n3.Exit \nEnter your option: ");
 scanf("%d",&op);
 switch(op)
 {
 case 1:
     for (i=0;i<tsize;i++)
     hash[i]=-1 ;

     for(k=0;k<n;k++)
     {
  key=arr[k] ;
  i = hasht(key);
  while (hash[i]!=-1)
  {
      i = rehashl(i);
  }
  hash[i]=key ;
     }
     printf("\nThe elements in the array are: ");
     for (i=0;i<tsize;i++)
     {
  printf("\n  Element at position %d: %d",i,hash[i]);
     }
     break ;

 case 2:
     for (i=0;i<tsize;i++)
  hash[i]=-1 ;

     for(k=0;k<n;k++)
     {
  j=1;
  key=arr[k] ;
  i = hasht(key);
  while (hash[i]!=-1)
  {
      i = rehashq(i,j);
      j++ ;
  }
  hash[i]=key ;
     }
     printf("\nThe elements in the array are: ");
     for (i=0;i<tsize;i++)
     {
  printf("\n Element at position %d: %d",i,hash[i]);
     }
     break ;

 }
    }while(op!=3);

    getch() ;
}

/* OUTPUT

Enter the size of the hash table:  10

Enter the number of elements: 8
Enter Elements: 72 27 36 24 63 81 92 101


1.Linear Probing
2.Quadratic Probing
3.Exit
Enter your option: 1

The elements in the array are:
  Element at position 0: -1
  Element at position 1: 81
  Element at position 2: 72
  Element at position 3: 63
  Element at position 4: 24
  Element at position 5: 92
  Element at position 6: 36
  Element at position 7: 27
  Element at position 8: 101
  Element at position 9: -1

1.Linear Probing
2.Quadratic Probing
3.Exit
Enter your option: 2

The elements in the array are:
 Element at position 0: -1
 Element at position 1: 81
 Element at position 2: 72
 Element at position 3: 63
 Element at position 4: 24
 Element at position 5: 101
 Element at position 6: 36
 Element at position 7: 27
 Element at position 8: 92
 Element at position 9: -1

1.Linear Probing
2.Quadratic Probing
3.Exit
Enter your option: 3
*/