Lab_12

#include <stdio.h>
#include <stdlib.h>
int i;
struct set
{
int key;
int data;
};
struct set *array;
int capacity = 10;
int size = 0;
int hashFunction(int key)
{
return (key % capacity);
}
int checkPrime(int n)
{
int i;
if (n == 1 || n == 0)
{
return 0;
}
for (i = 2; i < n / 2; i++)
{
if (n % i == 0)
{
return 0;
}
}
return 1;
}
int getPrime(int n)
{
if (n % 2 == 0)
{
n++;
}
while (!checkPrime(n))
{
n += 2;
}
return n;
}

void init_array()
{
capacity = getPrime(capacity);
array = (struct set *)malloc(capacity * sizeof(struct set));
for (i = 0; i < capacity; i++)
{
array[i].key = 0;
array[i].data = 0;
}
}

void insert(int key, int data)
{
int index = hashFunction(key);
if (array[index].data == 0)
{
array[index].key = key;
array[index].data = data;
size++;
printf("\n Key (%d) has been inserted \n", key);
}
else if (array[index].key == key)
{
array[index].data = data;
}
else
{
printf("\n Collision occured \n");
}
}

void remove_element(int key)
{
int index = hashFunction(key);
if (array[index].data == 0)
{
printf("\n This key does not exist \n");
}
else
{
array[index].key = 0;
array[index].data = 0;
size--;
printf("\n Key (%d) has been removed \n", key);
}
}

void display()
{
int i;
for (i = 0; i < capacity; i++)
{
if (array[i].data == 0)
{
printf("\n array[%d]: / ", i);
}
else
{
printf("\n key: %d array[%d]: %d \t", array[i].key, i, array[i].data);
}
}
}

int size_of_hashtable()
{
return size;
}

int main()
{
int choice, key, data, n;
int c = 0;
init_array();
clrscr();

do
{
printf("1.Insert item in the Hash Table"
"\n2.Remove item from the Hash Table"
"\n3.Check the size of Hash Table"
"\n4.Display a Hash Table\n 5 exit"
"\n\n Please enter your choice:
");
scanf("%d", &choice);

switch (choice)
{

case 1:printf("Enter key -:\t");
scanf("%d", &key);
printf("Enter data -:\t");
scanf("%d", &data);
insert(key, data);
break;
case 2: printf("Enter the key to delete:");
scanf("%d", &key);
remove_element(key);
break;

case 3: n = size_of_hashtable();
printf("Size of Hash Table is-:%d\n", n);
break;

case 4: display();
break;

case 5:exit(0);
default: printf("Invalid Input\n");

}
printf("\nDo you want to continue (press 1 for yes): ");
scanf("%d", &c);
}

while (c == 1);
getch();
return 0;
}