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LINKED LIST
#include <stdio.h>
#include <stdlib.h>
struct node
{
    int data;
    struct node *next;
};
struct node * insert(struct node *head, int data)
{
    struct node *newnode = (struct node *)malloc(sizeof(struct node *));
    newnode->data = data;
    newnode->next = head;
    return newnode;
}
void traversal(struct node *ptr)
{
    while (ptr != NULL)
    {
        printf("%d", ptr->next);
        ptr = ptr->next;
    }
}
struct node * insertmid(struct node *head, int data,int index)
{
    struct node *newnode = (struct node *)malloc(sizeof(struct node *));
    struct node * ptr=NULL;
    ptr=head;
    for (int i = 0; i < (index-1); i++)
    {
        ptr=ptr->next;
    }
    newnode->data=data;
    newnode->next=ptr->next;
    ptr->next=newnode;
    return head;
}
void printdata(struct node*head)
{
    if (head==NULL)
    {
        printf("linkedlist is empty");
    }
    struct node*ptr=NULL;
    ptr=head;
    while (ptr != NULL)
    {
       printf("%d\n",ptr->data);
       ptr=ptr->next;
    }
    

}
int main()
{
    struct node *head;  
    struct node *secound;  
    struct node *third;  
    struct node *fourth;  
    head=(struct node *)malloc(sizeof(struct node));
    secound=(struct node *)malloc(sizeof(struct node));
    third=(struct node *)malloc(sizeof(struct node));
    fourth=(struct node *)malloc(sizeof(struct node));
    head->data=40;
    head->next=secound;
    secound->data=56;
    secound->next=third;
    third->data=90;
    third->next=fourth;
    fourth->data=69;
    fourth->next=NULL;
     printf("before insertion\n");
    printdata(head);
    printf("after insertion\n");
    head=insert(head,56);
    printdata(head);
    printf("after insertionin middle\n");
    head=insertmid(head,100,2);
    printdata(head);
    return 0;
}