text: struct ListNode* reverseList(struct ListNode *head) {
          
      if(!head) return NULL;
          
          struct ListNode *curr=head,*prev=NULL,*next;
  	
  
  	
  	while(curr)
  	
  	{
  		next = curr->next;
  		curr->next = prev; //making backwards link
  		prev = curr;
  		curr = next;
  		
  	}
  
  	return prev;
  }
  