HASH FUNCTION-C

 

HASH FUNCTION

QUESTION:

Given a File of N employee records with a set K of Keys (4-digit) which uniquely determine

the records in file F. Assume that file F is maintained in memory by a Hash Table (HT) of m

memory locations with L as the set of memory addresses (2-digit) of locations in HT. Let the

keys in K and addresses in L are Integers. Develop a Program in C that uses Hash function H:

K →L as H(K)=K mod m (remainder method), and implement hashing

technique to map a given key K to the address space L. Resolve the collision (if any) using

linear probing.

PROGRAM:

#include<stdio.h>

#include<stdlib.h>

 int key[20],n,m;

int *ht,index;

int count = 0;

 void insert(int key)

{

            index = key % m;

            while(ht[index] != -1)

            {

                         index = (index+1)%m;

            }

            ht[index] = key;

            count++;

 }

 

void display()

{

           int i;

           if(count == 0)

          {

                         printf("\nHash Table is empty");

                         return;

           }

            printf("\nHash Table contents are:\n ");

           for(i=0; i<m; i++)

                      printf("\n T[%d] --> %d ", i, ht[i]);

}

 void main()

{

         int i;

         printf("\nEnter the number of employee  records (N) :   ");

         scanf("%d", &n);

          printf("\nEnter the two digit memory locations (m) for hash table:   ");

         scanf("%d", &m);

          ht = (int *)malloc(m*sizeof(int));

         for(i=0; i<m; i++)

                     ht[i] = -1;

          printf("\nEnter the four digit key values (K) for N Employee Records:\n  ");

         for(i=0; i<n; i++)

                    scanf("%d", &key[i]);

          for(i=0;i<n;i++)

        {

                   if(count == m)

                   {

                        printf("\n~~~Hash table is full. Cannot insert the record %d key~~~",i+1);

                        break;

                   }

                   insert(key[i]);

    }

             //Displaying Keys inserted into hash table

             display();

}

 

OUTPUT: