implementation of Hash table using arrays in C

#include<stdio.h>

#define size 7

int arr[size];

void init()

{   int i;

    for(i = 0; i < size; i++)

        arr[i] = -1;

}

 

void insert(int value)

{   int key = value % size;

    if(arr[key] == -1)

    {  

      arr[key] = value;

      printf("%d inserted at arr[%d]\n", value,key);

    }

    else

    {  

      printf("Collision : arr[%d] has element %d already!\n",key,arr[key]);

      printf("Unable to insert %d\n",value);

    }

}

 

void del(int value)

{   int key = value % size;

    if(arr[key] == value)

        arr[key] = -1;

    else

        printf("%d not present in the hash table\n",value);

}

 

void search(int value)

{   int key = value % size;

    if(arr[key] == value)

        printf("Search Found\n");

    else

        printf("Search Not Found\n");

}

 

void print()

{   int i;

    for(i = 0; i < size; i++)

        printf("arr[%d] = %d\n",i,arr[i]);

}

 

int main()

{   init();

    insert(10); //key = 10 % 7 ==> 3

    insert(4);  //key = 4 % 7  ==> 4

    insert(2);  //key = 2 % 7  ==> 2

    insert(3);  //key = 3 % 7  ==> 3 (collision)

 

    printf("Hash table\n");

    print();

    printf("\n");

 

    printf("Deleting value 10..\n");

    del(10);

    printf("After the deletion hash table\n");

    print();

    printf("\n");

 

    printf("Deleting value 5..\n");

    del(5);

    printf("After the deletion hash table\n");

    print();

    printf("\n");

 

    printf("Searching value 4..\n");

    search(4);

    printf("Searching value 10..\n");

    search(10);

    return 0;

}