Hashing-OpenAddressing.c

#include<stdio.h>
#include<stdlib.h>
#define size 100
int n;
struct node
{
    int data;
    struct node *next;
};

struct node *head[size] = {NULL}, *c;

int hash(int key)
{
    return (key % n);
}

void insert()
{
    int i, key;
    struct node *newnode;
    printf("Enter value to insert into hash table : ");
    scanf("%d", &key);
    i = hash(key);
    newnode = (struct node*)malloc(sizeof(struct node));
    newnode -> data = key;
    newnode -> next = NULL;
    if(head[i] == NULL)
        head[i] = newnode;
    else
    {
        c = head[i];
        while(c -> next!=NULL)
            c = c -> next;
        c -> next = newnode;
    }
}

void search()
{
    int key, i;
    printf("Enter element to be searched : ");
    scanf("%d", &key);
    i = hash(key)
    if(head[i] == NULL)
        printf("Element not found\n");
    else
    {
        for(c = head[i]; c != NULL; c = c->next)
        {
            if(c -> data == key)
            {
                printf("Search element found\n");
                return;
            }
        }
        printf("Search element not found\n");
    }
}

void display()
{
    int i;
    for(i = 0; i < n; i++)
    {
        printf("Entries at index %d : ", i);
        if(head[i] == NULL)
            printf("No hash entry\n");
        else
        {
            for(c = head[i]; c != NULL; c = c -> next)
                printf("%d -> ", c -> data);
            printf("\n");
        }
    }
}

void main()
{
    int op, i;
    printf("Enter the table size : ");
    scanf("%d", &n);
    while(1)
    {
        printf("1.Insert\t2.Display\t3.Search\t4.Exit\n");
        scanf("%d", &op);
        switch(op)
        {
            case 1: insert(); display(); break;
            case 2: display(); break;
            case 3: search(); break;
            case 4: exit(0);
        }
    }
}