Deletion in Linked list

 

#include <stdio.h>

#include<stdlib.h>

struct node{

    int data;

    struct node *link;

};

struct node *del_beg(struct node *head){

    struct node *ptr = head;

    head = head->link;

    free(ptr);

    return head;

}

struct node *del_pos(struct node *head, int pos){

    struct node *p = head;

    struct  node *q = head->link;

    for (int i = 0; i < pos-1; i++)

    {

        p = p->link;

        q = q->link;

    }

    p->link = q->link;

    free(q);

    return head;

   

}

struct node *del_end(struct node * head){

    struct node *p = head;

    struct  node *q = head->link;

while(q->link != NULL)

    {

        p = p->link;

        q = q->link;

    }

    p->link = NULL;

    free(q);

    return head;

   

}

void display(struct node *head){

    while(head!=NULL){

        printf(" %d ",head->data);

        head = head->link;

    }

}

int main()

{

   

      struct node *head;

    struct node *b;

    struct node *c;

    struct node *d;

   

    head = malloc(sizeof(struct node));

    b = malloc(sizeof(struct node));

    c = malloc(sizeof(struct node));

    d = malloc(sizeof(struct node));

   

    head->data = 1;

    head->link = b;

    b->data = 2;

    b->link = c;

    c->data = 3;

    c->link = d;

    d->data = 4;

    d->link = NULL;

   

   display(head);

   head = del_beg(head);

head = del_pos(head,4);

head = del_end(head);

   printf("\n");

   display(head);

    return 0;

}