hash.c

#include<stdio.h>
#include<stdlib.h>
#define LIMIT 5
enum record_status {EMPTY, DELETED, OCCUPIED};
struct Employee
{
  int employee_id, employee_age;
  char employee_name[30];
};
struct Record
{
  struct Employee info;
  enum record_status status;
};
int hash_function(int key)
{
  return (key % LIMIT);
}
int search_records(int key, struct Record hash_table[])
{
    int count, temp, position;
    temp = hash_function(key);
    position = temp;
    for(count = 1; count != LIMIT - 1; count++)
    {
      if(hash_table[position].status == EMPTY)
      {
        return -1;
      }
      if( hash_table[position].info.employee_id == key)
      {
        return position;
      }
      position = (temp + count) % LIMIT;
    }
    return -1;
}
void insert_records(struct Employee emprec, struct Record hash_table[])
{
  int count, position, temp;
  int key = emprec.employee_id;
  temp = hash_function(key);
  position = temp;
  for(count = 1; count != LIMIT - 1; count++)
  {
    if(hash_table[position].status == EMPTY || hash_table[position].status == DELETED)
    {
      hash_table[position].info = emprec;
      hash_table[position].status = OCCUPIED;
      printf("\nRecord Inserted into Hash Table\n");
      return;
    }
    if(hash_table[position].info.employee_id == key)
    {
      printf("\nDuplicate Record cannot be Inserted\n");
      return;
    }
    position = (temp + count) % LIMIT;
  }
  printf("\nHash Table Limit Exceeded\n");
}
void display_records(struct Record hash_table[])
{
 int count;
 printf("\nHash Table\n");
 for(count = 0; count < LIMIT; count++)
 {
   printf("[%d]:", count);
   if(hash_table[count].status == OCCUPIED)
   {
       printf("Occupied - ID: %d Name: %s Age: %d",hash_table[count].info.employee_id, hash_table[count].info.employee_name, has
h_table[count].info.employee_age);
   }
   printf("\t");
 }
}
void delete_records(int key, struct Record hash_table[])
{
   int position = search_records(key, hash_table);
   if(position == -1)
   {
       printf("\nKey Not Found\n");
   }
   else
   {
      hash_table[position].status = DELETED;
   }
}
int main()
{
   int count, key, option;
   struct Record hash_table[LIMIT];
   struct Employee emprec;
   for(count = 0; count <= LIMIT - 1; count++)
   {
      hash_table[count].status = EMPTY;
   }
   while(1)
   {
     printf("\n\t1. Insert a Record");
     printf("\n\t2. Delete a Record");
     printf("\n\t3. Search a Record");
     printf("\n\t4. Display All Records");
     printf("\n\t5. Exit");
     printf("\n\tEnter Your Option:\n\t");
     scanf("%d", &option);
     switch(option)
     {
       case 1: printf("\n\tEnter Employee ID:\n\t");
               scanf("%d", &emprec.employee_id);
               printf("\n\tEnter Employee Name:\n\t");
               scanf("%s", emprec.employee_name);
               printf("\n\tEnter Employee Age:\n\t");
               scanf("%d", &emprec.employee_age);
               insert_records(emprec, hash_table);
               break;

       case 2: printf("\n\tEnter the Key to Delete:\n\t");
               scanf("%d", &key);
               delete_records(key, hash_table);
               break;
       case 3: printf("\n\tEnter the Key to Search:\n\t");
               scanf("%d", &key);
               count = search_records(key, hash_table);
               if(count == -1)
               {
                 printf("\n\tRecord Not Found\n\t");
               }
               else
               {
                 printf("\n\tRecord Found at Index Position:\t%d\n\t", count);
               }
               break;
       case 4: display_records(hash_table);
               break;

       case 5: exit(1);
     }
   }
return 0;
}