Assignment 2
C-2.1 Describe, in pseudo-code, a link-hopping method for finding the middle node of a
doubly linked list with header and trailer sentinels, and an odd number of real nodes
between them. (Note: This method can only use link-hopping; it cannot use a counter.)
What is the running time of this method?
C-2.2 Describe, in pseudo-code, how to implement the queue ADT using two stacks.
What is the running time of the enqueue() and dequeue() methods in this case?
C-2.3 Describe how to implement the stack ADT using two queues. What is the running
time of the push() and pop() methods in this case?
A. Design a pseudo code algorithm to take a Sequence and remove all duplicate elements
from the Sequence. Is the algorithm the same for both a List or a Sequence? Explain.
Analyze your algorithm twice, once assuming it is a Sequence and once assuming it is a
List. Which ADT is a better choice for this problem, i.e., does one version have a better
running time over the other?
B. Describe a recursive algorithm for enumerating all subsets of the numbers
{1,2,…,n}, i.e., the powerset of the elements of a Sequence; the result should be a
Sequence containing Sequences. What is the running time of your method?
R-2.1 Describe, using pseudo-code, implementations of the methods insertBefore(p,e) ,
insertFirst(e), and insertLast(e) of the List ADT, assuming the list is implemented using
a doubly-linked list.
Optional if you have time:
C-2-5 Describe the structure and pseudo-code for an array-based implementation of the
vector ADT that achieves O(1) time for insertions and removals at rank 0, as well as
insertions and removals at the end of the vector. Your implementation should also
provide for a constant-time elemAtRank method.
