public Node shuffleMerge(Node head1, Node head2){
        if(head1 == null || head2 == null){
            return head2;
        }
        
        Node tempHead = head1;
        Node prev = null;
        while(head1 != null && head2 != null){
            Node temp = head1.next;
            Node temp1 = head2.next;
            head1.next = head2;
            head2.next = temp;
            prev = head2;
            head2 = temp1;
            head1 = temp;
        }
        if(head2 != null){
            prev.next = head2;
        }
        return tempHead;
    }
Size of list 1 is smaller, equal and larger than list 2
src/com/interview/linklist/ShuffleMerge.java