insertLL.c

#include <stdio.h>
#include <stdlib.h>
struct Node
{
    int data;
    struct Node *next;
} *first=NULL;

void create(int A[], int n)
{
    int i;
    struct Node *t, *last;
    first=(struct Node *)malloc(sizeof(struct Node));
    first->data=A[0];
    last=first;
    for(i=1;i<n;i++)
    {
        t=(struct Node*)malloc(sizeof(struct Node));
        t->data=A[i];
        t->next=NULL;
        last->next=t;
        last=t;
    }
}
int count(struct Node *p)
{
    int l=0;
    while(p)
    {
        l++;
        p= p->next;
    }
    return l;
}
void Display(struct Node *p)
{
    while(p!=NULL)
    {
        printf("%d\t",p->data);
        p=p->next;
    }
}
void Insert(struct Node *p, int index, int x)
{
    struct Node *t;
    if(index<0 || index > count(p))
        return;
    t=(struct Node *)malloc(sizeof(struct Node));
    t->data=x;
    if (index == 0)
    {
        t->next=first;
        first=t;
    }
    else
    {
        for(int i=0;i<index-1;i++)
            p=p->next;
        t->next=p->next;
        p->next=t;
    }
}
int main()
{
    int A[]={3,5,7};
    create(A,3);
    Insert(first,2,10);
    Display(first);
}