It is known that the two linked lists head1 and head2 are in an orderly order. Please combine them into a linked list. (Keep all nodes, even if the size is the same)

 

Node * Merge (node * head1, node * head2)
{
If (head1 = NULL)
Return head2;
If (head2 = NULL)
Return head1;
Node * head = NULL;
Node * P1 = NULL;
Node * P2 = NULL;
If (head1-> data {
Head = head1;
P1 = head1-> next;
P2 = head2;
}
Else
{
Head = head2;
P2 = head2-> next;
P1 = head1;
}
Node * pcurrent = head;
While (P1! = NULL & p2! = NULL)
{
If (P1-> data <= P2-> data)
{
Pcurrent-> next = p1;
Pcurrent = p1;
P1 = p1-> next;
}
Else
{
Pcurrent-> next = P2;
Pcurrent = P2;
P2 = P2-> next;
}
}
If (P1! = NULL)
Pcurrent-> next = p1;
If (P2! = NULL)
Pcurrent-> next = P2;
Return head;
}