Python code:

def mergeLists(head1, head2):

dummy = SinglyLinkedListNode(0)

current = dummy   

while head1 is not None and head2 is not None:

    if head1.data < head2.data:

        current.next = head1

        head1 = head1.next      

    elif head1.data == head2.data:

        current.next = head1

        head1 = head1.next

        current = current.next

        current.next = head2

        head2 = head2.next      

    else:

        current.next = head2

        head2 = head2.next     

    current = current.next

    # Attach remaining nodes from either list

if head1 is not None:

        current.next = head1
elif head2 is not None:
        current.next = head2

return dummy.next

Python code:

def mergeLists(head1, head2):

if head1 is None:
    return head2
if head2 is None:
    return head1

if (head1.data < head2.data):
    head1.next = mergeLists(head1.next, head2)
    return head1
else:
    head2.next = mergeLists(head2.next, head1)
    return head2

def mergeLists(head1, head2): dummy = SinglyLinkedListNode(0) tail = dummy

while head1 and head2:
    if head1.data < head2.data:
        tail.next = head1
        head1 = head1.next
    else:
        tail.next = head2
        head2 = head2.next
    tail = tail.next

tail.next = head1 if head1 else head2
return dummy.next

Problem explanation is incorrect in the example. There is no 7 in either input LinkedList.

Merging two sorted linked lists is a classic linked list problem, often asked in technical interviews and widely used in algorithms like merge sort. Cricbet99 Green Sign Up