HASHING.BAK

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<conio.h>
struct hash *hashTable=NULL;
int elementCount = 0;
struct node{
int key;
struct node *next;
};
struct hash{
struct node *head;
int count;
};
struct node * createNode(int key)
{
struct node *newNode;
newNode=(struct node *)malloc(sizeof(struct node));
newNode->key = key;
newNode->next=NULL;
return newNode;
}
void insertion(int key)
{
int hashIndex = key % elementCount;
struct node *newNode= createNode(key);
if(!hashTable[hashIndex].head)
{
hashTable[hashIndex].head=newNode;
hashTable[hashIndex].count=1;
return;
}
newNode->next=(hashTable[hashIndex].head);
hashTable[hashIndex].head=newNode;
hashTable[hashIndex].count++;
return;
}
void deletion(int key)
{
int hashIndex=key%elementCount, flag=0;
struct node *temp, *myNode;
myNode=hashTable[hashIndex].head;
if(!myNode)
{
printf("Given data is not present in hash table.");
return;
}
temp = myNode;
while(myNode!=NULL)
{
if(myNode->key==key)
{
flag=1;
if(myNode==hashTable[hashIndex].head)
hashTable[hashIndex].head=myNode->next;
else
temp->next=myNode->next;
hashTable[hashIndex].count--;
free(myNode);
break;
}
temp=myNode;
myNode=myNode->next;
}
if(flag)
printf("Data deleted from hash table successfully");
else
printf("Given data is not present in hash table");
return;
}
void search(int key)
{
int hashIndex=key%elementCount, flag=0;
struct node *myNode;
myNode=hashTable[hashIndex].head;
if(!myNode)
{
printf("Element is not present in the hash table");
return;
}
while(myNode!=NULL)
{
if(myNode->key==key)
{
printf("Key Found: %d", myNode->key);
flag=1;
break;
}
myNode=myNode->next;
}
if(!flag)
printf("Element is not present in the hash table");
return;
}
void display()
{
struct node *myNode;
int i;
for(i=0; i<elementCount; i++)
{
if(hashTable[i].count==0)
continue;
myNode=hashTable[i].head;
if(!myNode)
continue;
printf("Data at index %d in hash table:", i);
while(myNode!=NULL)
{
printf("%-12d", myNode->key);
myNode=myNode->next;
}
}
return;
}
void main()
{
int n, key, ch;
printf("\n Enter the number of elements:");
scanf("%d", &n);
elementCount=n;
hashTable=(struct hash *)calloc(n, sizeof(struct hash));
while(1)
{
printf("\n 1. Insertion");
printf("\n 2. Deletion");
printf("\n 3. Searching");
printf("\n 4. Display");
printf("\n 5. Exit");
printf("\n Enter your choice:");
scanf("%d", &ch);
switch(ch)
{
case 1: printf("\n Enter the key value:");
	scanf("%d", &key);
	getchar();
	insertion(key);
	break;
case 2: printf("\n Enter the key to perform deletion:");
	scanf("%d", &key);
	deletion(key);
	break;
case 3: printf("\n Enter the key to search:");
	scanf("%d", &key);
	search(key);
	break;
case 4: display();
	break;
case 5: exit(0);
default: printf("Wrong Option");
	 break;
}
}
getch();
}