Question 1 A non-circular, singly linked list Abstract Data Type has a private Node pointer, called first , which points to the rst node of the list. This ADT does not maintain a header pointer to the last node of the list, but it does maintain a variable size to keep track of the number of nodes in the list. Given a pointer to a node n , assume that values can be read or written to by using the eld names n.val and n.next for the value and next elds of the node respectively. Assume that a garbage collector is being used, so nodes do not need to be explicitly freed. Use END for invalid or null address pointer values. (a) delete nth(int n) is a non-recursive method of the ADT that removes node number nfrom the list and throws an IllegalArgumentException if no such element exists or if nis less than 0. The rst node is numbered 0. Fill in the missing part of the pseudocode for this function below: 1 v o i d d e l e t e n t h ( i n t n ) 2 f 3 / / WRITE THE CODE THAT SHOULD BE HERE 4 r e t u r n 5 g (b) Assume that this ADT has two di erent di erent methods to delete all the elements from the singly linked list as follows: 1 v o i d d e l e t e a l l f r o m s t a r t ( ) 2 f 3 w h i l e ( s i z e >0 ) 4 d e l e t e n t h ( 0 ) 5 r e t u r n 6 g 7 8 v o i d d e l e t e a l l f r o m e n d ( ) 9 f 10 w h i l e ( s i z e >0 ) 11 d e l e t e n t h ( s i z e 1 ) 12 r e t u r n 13 g Give the complexities of these two methods in big O notation and explain how you derived them. Write the pseudocode for a much simpler and more ecient method to delete all elements from the list.