JAVA Help:

6) A circularly linked list is used to represent a Queue. A single variable P is used to access the Queue. To which Node should P point such that both the operations enqueue (item) and item = dequeue() can be performed in constant time: O(1) no looping necessary?

7)

Show what is written by the following segment of code:

stack = new MyStack();

String item0 = ;

String item1 = EE;

String item2 = B + item1;

String item3 = P;

push (item2);

push (item1);

push (item3 + item1);

item0 = stack.peek();

pop();

push (item2 + item3);

push (item0);

push (item0 + item3);

item0 = stack.peek();

pop();

print (Item0: + item0);

print (Item1: + item1);

print (Item2: + item2);

print (Item3: + item3);

while (!stack.isEmpty())

item0 = stack.peek();

pop();

print (Item: + item0);

8)

A single array, stk[MAXELEMS], is used to implement two stacks. The two stacks are grown in an array one from each end. Two variables, head1 and head2 (head1 < head2), hold the index of the location of the top element in each of the stacks. Which of the following is the best for implementing the check for a full stack, given we want a space efficient algorithm.

A) (head1 = MAXELEMS / 2) and (head2 = MAXELEMS / 2+1)

B) head1 + head2 = MAXELEMS

C) (head1 = MAXELEMS / 2) or (head2 = MAXELEMS)

D) head1 = head2 1