Consider the problem of reversing a singly linked list. To take an example, given the linked list below:

the reversed linked list should look like

Which one of the following statements is TRUE about the time complexity of algorithms that solve the above problem in O(1) space?

What is the worst case time complexity of inserting n elements into an empty linked list, if the linked list needs to be maintained in sorted order?

$$N$$ items are stored in a sorted doubly linked list. For a $$delete$$ operation, a pointer is provided to the record to be deleted. For a $$decrease$$-$$key$$ operation, a pointer is provided to the record on which the operation is to be performed.

An algorithm performs the following operations on the list in this order:
$$\Theta \left( N \right),\,\,delete,\,\,O\left( {\log N} \right)\,insert,\,$$ $$\,O\left( {\log N} \right)\,fund, and $$ $$\Theta \left( N \right)\,$$ $$decrease$$-$$key.$$ What is the time complexity of all these operations put together?

Let P be a singly linked list, Let Q be the pointer to an intermediate node x in the list.What is the worst-case time complexity of the best known algorithm to delete the node x from the list?