A. Delete the first element of the list
Pointer F will be set to next node, so does not depends on length of linked list.
B.Interchange the first two elements of the list.
Again this can be performed using a temp node and does not depends on length of linked list.
C. Delete the last element of the list
In this we need to get the address of the node just before the last node, because let address of node before last node is (1000) then we need to set this address to (1000)->next=NULL. So calculating this address we need to linear search the linked list and so it depends on length of linked list.
D.Add an element at the end of the list
Here , we know the address of last node due pointer L.So just do L->next=new node.So does not depends on length of linked list. .