Reverse of a linked list without recursion created by Rohik - https://repl.it/@Rohik/Reverse-of-a-linked-list-without-recursion

Reverse of a linked list without recursion.c

#include <stdio.h>
#include <stdlib.h>
struct tnode
{
int data;
struct tnode *link;
};
typedef struct tnode *tptr;
tptr insert(tptr first,int x)
{
   tptr p,t;
   p=(tptr)malloc(sizeof(struct tnode));
   p->data=x;
   p->link=NULL;
   if(first==NULL)
   {
   first=p;
   return first;
   }
   t=first;
   while(t->link!=NULL)
   t=t->link;
   t->link=p;
   return first;

}
void display(tptr first)
{
   tptr t;
   t=first;
    while(t!=NULL)
    {
      printf("%d ",t->data);
      t=t->link;
    }
}
tptr reverse(tptr head)
{
  tptr prev=NULL,next=NULL,current=NULL;
  current=head;
  while(current!=NULL)
  {
    next=current->link;
    current->link=prev;
    prev=current;
    current=next;
  }
  return prev;
}

int main()
{
  int x;
  tptr first;
  first=NULL;

  scanf("%d",&x);
  while(x!=-1)
  {
    first=insert(first,x);
    scanf("%d",&x);
  }
  first=reverse(first);
  display(first);
  return 0;
}