COP 3530 Section 5                           EXAM 1                     February 13, 2003

 

Kraynek                                                                                 Name:_______________

 

10 points

1. True of False for Java Classes and/or Interfaces

 

  1. AbstractList is a subclass of AbstractCollection  T or F

 

  1. An interface variable can be assigned any variable T or F

 

  1. The boolean contains(Object x) method of TreeSet is O(1)  T or F

 

  1. The boolean contains(Object x) method of LinkedList is O(n)  T or F

 

  1. The Comparator interface should be implemented in a class by itself T or F

 

 

 

 

 

 

15 pts.

2. What is the output of the following segment?

            String out = "";

            List list = new LinkedList();

            ListIterator itr = list.listIterator();

            itr.add(new Integer(1));

            itr.add(new Integer(2));

            itr.add(new Integer(3));

            itr.add(new Integer(4));

            itr = list.listIterator();

            System.out.println(list);

            itr.next();

            itr.next();

            itr.add(new Integer(37));

            System.out.println(list);

itr.previous();

            itr.remove();

            itr.next();

            println( itr.previous());

            itr.set(new Integer(37));

            System.out.println(list);

 

15 points

3. Write an O(n) (i.e. one pass through the list) method

            void removeAll(LinkedList l, Object x);

that removes all occurences of x form the Linkedlist l.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15 points

4. Consider

class DNode {

            Object data;

            DNode previous;

            DNode next;

            DNode(){}

            DNode(Object d, DNode p, DNode n) {

                        data = d;

previous = p;

next = n;

            }

} // end DNode

 

Suppose that DNode head references the list head in a circular doubly linked list with a list head. Write the method

 

            void removeLast(DNode head);

 

that removes the last DNode on the list. Include an error check if necessary.

 

15 points

5. Write a recursive method

 

            int countAnds(ArrayList a, int right);

 

that returns the number of “and”’s in the ArrayList of Strings a. Do not use any global variables.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5 points

6. What is the running time of the following method?

            void problem6(ArrayList a, int right) {

                        if( right < 0 ) return;

for( int i = 0; i < right; i++ ) {

                                    a.set(i,a.get(i+1));

} // end for

                        problem6(a,right - 1);

            }

                       


15 points

7. Consider the NCAA data file of Assignment Two. Write a main method to output to the screen each winning team along with all the years that team won a game. To read the data you can use

 

  BufferedReader in = new BufferedReader(new FileReader(“ncaa2002.data”);

  String aLine;

  while( (aLine = in.readLine()) != null ) {

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10 pts.

8. Describe how to construct a set whose iterator would return the teams from problem 7 in order of the number of years that team won a game from the most to the fewest.