Linklist insert

#include<stdio.h>
#include<stdlib.h>
struct node
{
    int data;
    struct node *link;
};
int main()
{
    int n;
    scanf("%d",&n);

    struct node *current,*first,*previous;

    for(int i=0; i<n; i++)
    {
        current=malloc(sizeof(struct node));
        int x;
        scanf("%d",&current->data);

        if(i==0)first=current;
        else
        {
            previous->link=current;
        }
        previous=current;
    }
    current->link=NULL;



    int in;
    scanf("%d",&in);

    struct node *p=first,*f,*a;

    f=malloc(sizeof(struct node));
    f->data=25;
    f->link=NULL;

    a=first;

    for(int i=1;i<=in-2;i++){
        a=a->link;
    }
    f->link=a->link;
    a->link=f;


    while(p!=NULL)
    {
        printf("%d\n",p->data);
        p=p->link;
    }

    return 0;
}