Lists - Data Structures and Abstractions with Java - page 314

3.

Revise the method displayList in Listing 12-2 so that it uses the list method toArray instead of methods getLength
and getEntry .

4.

Suppose that you want an operation for the ADT list that returns the position of a given object in the list. The
header of the method could be as follows:
public int getPosition(T anObject)
Write comments that specify this method.

5.

Suppose that you want an operation for the ADT list that removes the first occurrence of a given object from the
list. The header of the method could be as follows:
public boolean remove(T anObject)
Write comments that specify this method.

6.

Suppose that you want an operation for the ADT list that moves the first item in the list to the end of the list. The
header of the method could be as follows:
public void moveToEnd()
Write comments that specify this method.

7.

Write Java statements at the client level that return the position of a given object in the list myList . Assume that
the object is in the list.

8.

Suppose that the ADT list did not have a method replace . Write Java statements at the client level that replace an
object in the list nameList . The object's position in the list is givenPosition and the replacement object is newObject .

9.

Suppose that the ADT list did not have a method contains . Suppose further that nameList is a list of Name
objects, where Name is as defined in Appendix B. Write Java statements at the client level that see whether the
Name object myName is in the list nameList .

10.

Suppose that you have a list that is created by the following statement:
ListInterface<Student> studentList = new AList<Student>();
Imagine that someone has added to the list several instances of the class Student that Appendix C defined in Segment C.2.
a. Write Java statements that display the last names of the students in the list in the same order in which the
students appear in the list. Do not alter the list.
b. Write Java statements that interchange the first and last students in the list.

11.

Suppose that you have a list that is created by the following statement:
ListInterface<Double> quizScores = new AList<Double>();
Imagine that someone has added to this list the quiz scores received by a student throughout a course. The profes-
sor would like to know the average of these quiz scores, ignoring the lowest score.

a. Write Java statements at the client level that will find and remove the lowest score in the list.
b. Write Java statements at the client level that will compute the average of the scores remaining in the list.

12.

Consider a class Coin that represents a coin. The class has methods such as getValue , toss , and isHeads . The
method getValue returns the value, or denomination, of a coin. The method toss simulates a coin toss in which
the coin lands either heads up or tails up. The method isHeads returns true if a coin is heads up.
Suppose that coinList is an ADT list of coins that have randomly selected denominations. Toss each of these
coins. If the result of a coin toss is heads, move the coin to a second list called headsList ; if it is tails, leave the
coin in the original list. When you are finished tossing coins, compute the total value of the coins that came up
heads. Assume that the list headsList has been created for you and is empty initially.