CompareTwoLinkedLists.java

/*
You’re given the pointer to the head nodes of two linked lists.
Compare the data in the nodes of the linked lists to check if
they are equal. The lists are equal only if they have the same
number of nodes and corresponding nodes contain the same data.
Either head pointer given may be null meaning that the
corresponding list is empty.

Link: https://www.hackerrank.com/challenges/compare-two-linked-lists
*/

/*
  Compare two linked lists A and B
  Return 1 if they are identical and 0 if they are not.
  Node is defined as
  class Node {
     int data;
     Node next;
  }
*/
int CompareLists(Node headA, Node headB) {
    while (headA != null && headB != null) {
        if (headA.data != headB.data)
            return 0;
        headA = headA.next;
        headB = headB.next;
    }
    if (headA != null && headB == null)
        return 0;
    else if (headB != null && headA == null)
        return 0;
    else
        return 1;
}