CS

profilebasil101516
hw3.zip
Home>Computer Science homework help>CS

HW3/HW3.doc

CS 219 - HOMEWORK 3

(Due: Sun, 9/20/2015. Total: 20 pts; Extra credit: 2 pts)

HOMEWORK SUBMISSION POLICIES:

· Put all of your work, even project source code and screenshots of project output, into a single homework document, and submit that document into the course website's drop box by midnight of the day that the homework is due. Put your name at the top of that document. If you completed any of the extra credit work, add a paragraph to the beginning of your document explaining the part you attempted and the amount of extra credit you are claiming. Please also comment the corresponding part of your code with the phase “Extra credit work: …”

· Make sure that the problems in your homework document are in the same order as the problems in the homework assignment.

· In your homework document, make sure that you use monospace font (such as Courier New) for your project source code and project output. The monospace font ensures that text that's supposed to be aligned stays aligned when it's printed. If your printed source code is not aligned properly, you will lose style points.

Submit answers for all of the following questions.

EXERCISES (20 pts + 2 pts Extra Credit):

Java source code files for the following problems are in HW3.zip. Note that every given Java file already compiles and generates result.

1. (4 pts) (The complete code to use is in P1.java) Complete the tracing we did in class on Wed. Sep 9 (week 4) on the second test case. Use Eclipse’s debugging mode to step through the code to verify your tracing result.

(Trace execution on paper): Consider the following method:

10 public static void mystery(ArrayList<Integer> list)

11 {

12 for (int i = list.size() - 1; i > 0; i--)

13 {

14 if (list.get(i) < list.get(i - 1))

15 {

16 int element = list.get(i);

17 list.remove(i);

18 list.add(0, element);

19 }

20 } // end for

21 System.out.println(list);

22 } // end mystery

Write the output produced by the method when passed the following ArrayLists:

[30, 20, 10, 60, 50, 40]

a. (1 pt) The output is: ____________________________________

b. (2 pts) tracing table

line#

List

size()

I

i>0?

get(i)<get(i-1)?

element

11

[30, 20, 10, 60, 50, 40]

6

12

5

12

T

14

get(5)<get(4)?

40<50? T

c. (1 pts) Two screenshots of the Variables panel (image1.png) when running this program (P1.java) in Eclipse under Debugging mode:

i) when execution is at the first line in mystery() i.e. for loop heading line. Click open each [i] to show integer value inside (as shown below);

image2.png

ii) when execution reaches the println(list) line in mystery(). Again click open each [i] to have the integer value shown on your screenshot (as shown below).

image3.png

2. (5 pts) (Shell code in P2_MaxLength.java) Write a method maxLength that takes an ArrayList of Strings as a parameter and that returns the length of the longest string in the list. If your method is passed an empty list, it should return 0.

Hint:

· There are build-in ArrayList method to check if an ArrayList object is empty or not.

· There are build-in String method to return the length of a String object.

3. (4 pts) (Shell code in P3_DoubleList.java) Write a method doubleList that takes an ArrayList of Strings as a parameter and that replaces every string with two of that string. For example, if the list stores the values {"how", "are", "you?"} before the method is called, it should store the values {"how", "how", "are", "are", "you?", "you?"} after the method finishes executing.

4. (5 pts) (Shell code in P4_RemoveDuplicate.java) Write a method removeDuplicates that takes as a parameter a sorted ArrayList of Strings and that eliminates any duplicates from the list. For example, suppose that a variable called list contains the following values: {"be", "be", "is", "not", "or", "question", "that", "the", "to", "to"}. After calling removeDuplicates(list); the list should store the following values: {"be", "is", "not", "or", "question", "that", "the", "to"}

Because the values will be sorted, all of the duplicates will be grouped together.

5. (Extra Credit: 2 pts) (Shell code in P5_EC_FilterRange.java) Write a method filterRange that accepts an ArrayList of integers and two integer values min and max as parameters and removes all elements whose values are in the range min through max (inclusive) from the list. For example, if a variable called list stores the values:

[4, 7, 9, 2, 7, 7, 5, 3, 5, 1, 7, 8, 6, 7]

The call of filterRange(list, 5, 7); should remove all values between 5 and 7, therefore it should change the list to store [4, 9, 2, 3, 1, 8]. If no elements in range min-max are found in the list, the list's contents are unchanged. If an empty list is passed, the list remains empty. You may assume that the list is not null.

6. (1/2 pts) Answer this question AFTER you’ve completed this assignment:

What’s the hardest part of this assignment for you? Please explain.

Overall comment your program appropriately. Pay attention to standard stuff like coding style, indention, heading, and curly braces. Double check your code for indentation and alignment after you paste it into your homework document.

Submission: one single document including answers to all exercise questions

· Exercise 1: output result; tracing table; two screenshots

· Exercise 2 – 4 (and EC 5 if included): source code of the method (just that method, not the whole java file); screenshot of running program

· Use the rubric below to check the completeness of your work before turning it in.

Rubric: CS219, HW3

Item

Points

(Max)

Points (recvd)

Exercise (20 pts + 2 EC)

1. mystery: output result; tracing table; two screenshots

4

2. maxLength: source code of the method; screenshot

5

3. doubleList: source code of the method; screenshot

4

4. removeDuplicates: source code of the method; screenshot

5

(Extra Credit) 5. filterRange: source code of the method; screenshot

(2)

6. HW feedback

½

General (1½ pts)

Your project compiles and runs

½

Programming style

· Meaningful names for constants and variables

· Correct indentation: 2 spaces for each level

½

Comments

· Prolog

· End of section comments: end of class, end of method, end of loop etc.

· Document each variable

· Proper comments in the program

½

Penalty

Extra instance/class variables/methods

(- 1)

No copy of code in document

(- 1)

No screenshot of execution result

(- 1)

Total:

20+2EC

- END -

HW3/HW3_code/P1.java

HW3/HW3_code/P1.java

import  java . util . ArrayList ;
import  java . util . Arrays ;    // use Arrays.asList() method

public   class  P1
{
   public   static   void  main ( String []  args )
   {
     // case 1
     Integer []  intArr  =   new   Integer []{ 2 ,   6 ,   1 ,   8 };
     // first create an array of Integers: automatic boxing happens here
     //   automatic boxing happens here: convert each int to Integer obj and then initialize array of Integer

     ArrayList < Integer >  values  =   new   ArrayList < Integer > ( Arrays . asList ( intArr ));   // create an ArrayList obj from given Integer array
    mystery ( values );

     // case 2
     Integer []  intArr2  =   new   Integer []{ 30 ,   20 ,   10 ,   60 ,   50 ,   40 };
     // first create an array of Integers: automatic boxing happens here
     //   automatic boxing happens here: convert each int to Integer obj and then initialize array of Integer

     ArrayList < Integer >  values2  =   new   ArrayList < Integer > ( Arrays . asList ( intArr2 ));   // create an ArrayList obj from given Integer array
    mystery ( values2 );

     /*
    // case 3
    Integer[] intArr3 = new Integer[]{-4, 16, 9, 1, 64, 25, 36, 4, 49};
    // first create an array of Integers: automatic boxing happens here
    //   automatic boxing happens here: convert each int to Integer obj and then initialize array of Integer

    ArrayList<Integer> values3 = new ArrayList<Integer>(Arrays.asList(intArr3)); // create an ArrayList obj from given Integer array
    mystery(values3);
    */
   }   // end main

   public   static   void  mystery ( ArrayList < Integer >  list )
   {
     for   ( int  i  =  list . size ()   -   1 ;  i  >   0 ;  i -- )
     {
       if   ( list . get ( i )   <  list . get ( i  -   1 ))
       {
         int  element  =  list . get ( i );
        list . remove ( i );
        list . add ( 0 ,  element );
       }
     }   // end for
     System . out . println ( list );
   }   // end mystery

}   // end class P1

HW3/HW3_code/P2_MaxLength.java

HW3/HW3_code/P2_MaxLength.java

/*************************************************************************
 * CS219 Fall 2015
 * HW3
 *
 * (shell code)
 * maxLength
 * Write a method maxLength that takes an ArrayList of Strings as a
 * parameter and that returns the length of the longest string in the
 * list. If your method is passed an empty list, it should return 0.
**************************************************************************/

import  java . util . ArrayList ;   // to use ArrayList class
import  java . util . Arrays ;      // to use Arrays.toString(), Arrays.asList() methods
     // Arrays is a pre-defined class which contains various methods for
     // manipulating arrays
     // Java API: http://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html

public   class   P2_MaxLength
{
   public   static   void  main ( String []  args )
   {
     // testing case 1
     String []  arr1  =   { "to" ,   "be" ,   "or" ,   "not" ,   "to" ,   "be" ,   "hamlet" };
     int  result1  =   6 ;
    test ( arr1 ,  result1 );

     // testing case 2
     String []  arr2  =   { "to" ,   "be" ,   "or" ,   "not" ,   "to" ,   "be" };
     int  result2  =   3 ;
    test ( arr2 ,  result2 );

     // testing case 3
     String []  arr3  =   { "biggest" ,   "next" ,   "not" };
     int  result3  =   7 ;
    test ( arr3 ,  result3 );

     // testing case 4
     String []  arr4  =   { "Only one really long string" };
     int  result4  =   27 ;
    test ( arr4 ,  result4 );

     // testing case 5
     String []  arr5  =   {};   // empty list
     int  result5  =   0 ;
    test ( arr5 ,  result5 );
   }   // end main

   //**********************************************************************

   // a testing shell to print input and testing result
   public   static   void  test ( String []  list ,   int  expectedResult )
   {
     ArrayList < String >  listArrList  =   new   ArrayList < String > ( Arrays . asList ( list ));   // create ArrayList out of array

     System . out . println ( "Testing:  "   +  listArrList );   // print content of array
     System . out . println ( "expected: "   +  expectedResult );   // print expected result
     int  actualResult  =  maxLength ( listArrList );   // call method that solves the problem
     System . out . println ( "actual:   "   +  actualResult );   // print result
     System . out . println (( expectedResult  ==  actualResult ) ?   "pass"   :   "fail" );   // testing status: pass or fail
     System . out . println ();   // empty line between testing cases
   }   // end test

   //**********************************************************************

   // actual method that solve the problem

   // maxLength: returns the length of the longest string in the ArrayList parameter
   public   static   int  maxLength ( ArrayList < String >  strs )
   {
     // ADD CODE

   }   // end maxLength


}   // end class P2_MaxLength

HW3/HW3_code/P3_DoubleList.java

HW3/HW3_code/P3_DoubleList.java

/*************************************************************************
 * CS219 Fall 2015
 * HW3
 *
 * (shell code)
 * doubleList
 * Write a method doubleList that takes an ArrayList of Strings as a
 * parameter and that replaces every string with two of that string.
**************************************************************************/

import  java . util . ArrayList ;   // to use ArrayList class
import  java . util . Arrays ;      // to use Arrays.toString(), Arrays.asList() methods
     // Arrays is a pre-defined class which contains various methods for
     // manipulating arrays
     // Java API: http://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html

public   class   P3_DoubleList
{
   public   static   void  main ( String []  args )
   {
     // testing case 1
     String []  arr1  =   { "how" ,   "are" ,   "you?" };
     String []  result1  =   { "how" ,   "how" ,   "are" ,   "are" ,   "you?" ,   "you?" };
    test ( arr1 ,  result1 );

     // testing case 2
     String []  arr2  =   { "I" ,   "am" ,   "great," ,   "thanks!" };
     String []  result2  =   { "I" ,   "I" ,   "am" ,   "am" ,   "great," ,   "great," ,   "thanks!" ,   "thanks!" };
    test ( arr2 ,  result2 );

     // testing case 3
     String []  arr3  =   { "One string only" };
     String []  result3  =   { "One string only" ,   "One string only" };
    test ( arr3 ,  result3 );

     // testing case 4
     String []  arr4  =   { "1" ,   "4" ,   "3" };
     String []  result4  =   { "1" ,   "1" ,   "4" ,   "4" ,   "3" ,   "3" };
    test ( arr4 ,  result4 );

     // testing case 5
     String []  arr5  =   {};
     String []  result5  =   {};
    test ( arr5 ,  result5 );
   }   // end main

   //**********************************************************************

   // a testing shell to print input and testing result
   public   static   void  test ( String []  list ,   String []  expectedResult )
   {
     ArrayList < String >  listArrList  =   new   ArrayList < String > ( Arrays . asList ( list ));   // create ArrayList out of array
     String  expectedResultStr  =   Arrays . toString ( expectedResult );   // save expected result as string

     System . out . println ( "Testing:  "   +  listArrList );   // print content of array
     System . out . println ( "expected: "   +  expectedResultStr );   // print expected result
    doubleList ( listArrList );   // call method with actual functionality
     System . out . println ( "actual:   "   +  listArrList );   // print result
     System . out . println (( expectedResultStr . equals ( "" + listArrList )) ?   "pass"   :   "fail" );   // testing status: pass or fail
     System . out . println ();   // empty line between testing cases
   }   // end test

   //**********************************************************************

   // actual method that solve the problem

   // doubleList: replaces every string from ArrayList parameter with two of that string
   public   static   void  doubleList ( ArrayList < String >  strs )
   {
     // ADD CODE

   }   // end doubleList


}   // end class P3_DoubleList


HW3/HW3_code/P4_RemoveDuplicates.java

HW3/HW3_code/P4_RemoveDuplicates.java

/*************************************************************************
 * CS219 Fall 2015
 * HW3
 *
 * (shell code)
 * removeDuplicates
 * Write a method removeDuplicates that takes as a parameter a sorted
 * ArrayList of Strings and that eliminates any duplicates from the list.
 * Because the values will be sorted, all of the duplicates will be
 * grouped together.
**************************************************************************/

import  java . util . ArrayList ;   // to use ArrayList class
import  java . util . Arrays ;      // to use Arrays.toString(), Arrays.asList() methods
     // Arrays is a pre-defined class which contains various methods for
     // manipulating arrays
     // Java API: http://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html

public   class   P4_RemoveDuplicates
{
   public   static   void  main ( String []  args )
   {
     // testing case 1
     String []  arr1  =   { "be" ,   "be" ,   "is" ,   "not" ,   "or" ,   "question" ,   "that" ,   "the" ,   "to" ,   "to" };
     String []  result1  =   { "be" ,   "is" ,   "not" ,   "or" ,   "question" ,   "that" ,   "the" ,   "to" };
    test ( arr1 ,  result1 );

     // testing case 2
     String []  arr2  =   { "duplicate" ,   "duplicate" ,   "duplicate" ,   "duplicate" ,   "duplicate" };
     String []  result2  =   { "duplicate" };
    test ( arr2 ,  result2 );

     // testing case 3
     String []  arr3  =   { "unique" };
     String []  result3  =   { "unique" };
    test ( arr3 ,  result3 );

     // testing case 4
     String []  arr4  =   { "be" ,   "is" ,   "not" ,   "or" ,   "question" ,   "that" ,   "the" ,   "to" };
     String []  result4  =   { "be" ,   "is" ,   "not" ,   "or" ,   "question" ,   "that" ,   "the" ,   "to" };
    test ( arr4 ,  result4 );

     // testing case 5
     String []  arr5  =   {};
     String []  result5  =   {};
    test ( arr5 ,  result5 );
   }   // end main

   //**********************************************************************

   // a testing shell to print input and testing result
   public   static   void  test ( String []  list ,   String []  expectedResult )
   {
     ArrayList < String >  listArrList  =   new   ArrayList < String > ( Arrays . asList ( list ));   // create ArrayList out of array
     String  expectedResultStr  =   Arrays . toString ( expectedResult );   // save expected result as string

     System . out . println ( "Testing:  "   +  listArrList );   // print content of array
     System . out . println ( "expected: "   +  expectedResultStr );   // print expected result
    removeDuplicates ( listArrList );   // call method with actual functionality
     System . out . println ( "actual:   "   +  listArrList );   // print result
     System . out . println (( expectedResultStr . equals ( "" + listArrList )) ?   "pass"   :   "fail" );   // testing status: pass or fail
     System . out . println ();   // empty line between testing cases
   }   // end test

   //**********************************************************************

   // actual method that solve the problem

   // removeDuplicates: eliminates any duplicates from sorted ArrayList parameter
   public   static   void  removeDuplicates ( ArrayList < String >  strs )
   {
     // ADD CODE

   }   // end removeDuplicates


}   // end class P4_RemoveDuplicates


HW3/HW3_code/P5_EC_FilterRange.java

HW3/HW3_code/P5_EC_FilterRange.java

/*************************************************************************
 * CS219 Fall 2015
 * HW3
 *
 * (shell code)
 * (Extra Credit) filterRange
 * Write a method filterRange that accepts an ArrayList of integers and
 * two integer values min and max as parameters and removes all elements
 * whose values are in the range min through max (inclusive) from the
 * list.  If no elements in range min-max are found in the list, the
 * list's contents are unchanged. If an empty list is passed, the list
 * remains empty. You may assume that the list is not null.
**************************************************************************/

import  java . util . ArrayList ;   // to use ArrayList class
import  java . util . Arrays ;      // to use Arrays.toString(), Arrays.asList() methods
     // Arrays is a pre-defined class which contains various methods for
     // manipulating arrays
     // Java API: http://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html

import  java . util . ArrayList ;
import  java . util . Arrays ;    // use Arrays.asList() method

public   class   P5_EC_FilterRange
{
   public   static   void  main ( String []  args )
   {
     // case 1
     Integer []  intArr1  =   new   Integer []{ 4 ,   7 ,   9 ,   2 ,   7 ,   7 ,   5 ,   3 ,   5 ,   1 ,   7 ,   8 ,   6 ,   7 };
     int  min1  =   5 ,  max1  =   7 ;    // range
     Integer []  result1  =   new   Integer []{ 4 ,   9 ,   2 ,   3 ,   1 ,   8 };
    test ( intArr1 ,  min1 ,  max1 ,  result1 );

     // case 2
     Integer []  intArr2  =   new   Integer []{ - 8 ,   3 ,   5 ,   - 2 ,   12 ,   0 ,   - 4 ,   1 ,   - 10 };
     int  min2  =   - 5 ,  max2  =   5 ;    // range
     Integer []  result2  =   new   Integer []{ - 8 ,   12 ,   - 10 };
    test ( intArr2 ,  min2 ,  max2 ,  result2 );

     // case 3
     Integer []  intArr3  =   new   Integer []{ 4 ,   7 ,   9 ,   2 ,   7 ,   7 ,   5 ,   3 ,   5 ,   1 ,   7 ,   8 ,   6 ,   7 };
     int  min3  =   1 ,  max3  =   9 ;    // range
     Integer []  result3  =   new   Integer []{};
    test ( intArr3 ,  min3 ,  max3 ,  result3 );

     // case 4
     Integer []  intArr4  =   new   Integer []{ 4 ,   1 ,   9 ,   11 ,   3 ,   10 ,   14 ,   2 ,   12 };
     int  min4  =   5 ,  max4  =   8 ;    // range
     Integer []  result4  =   new   Integer []{ 4 ,   1 ,   9 ,   11 ,   3 ,   10 ,   14 ,   2 ,   12 };
    test ( intArr4 ,  min4 ,  max4 ,  result4 );

     // case 5
     Integer []  intArr5  =   new   Integer []{};
     int  min5  =   0 ,  max5  =   3 ;    // range
     Integer []  result5  =   new   Integer []{};
    test ( intArr5 ,  min5 ,  max5 ,  result5 );

   }   // end main

   //**********************************************************************

   // a testing shell to print input and testing result
   public   static   void  test ( Integer []  list ,   int  min ,   int  max ,   Integer []  expectedResult )
   {
     ArrayList < Integer >  listArrList  =   new   ArrayList < Integer > ( Arrays . asList ( list ));   // create ArrayList out of array
     String  expectedResultStr  =   Arrays . toString ( expectedResult );   // save expected result as string

     System . out . println ( "Testing:  "   +  listArrList  +   ", min "   +  min  +   ", max "   +  max );   // print content of array
     System . out . println ( "expected: "   +  expectedResultStr );   // print expected result
    filterRange ( listArrList ,  min ,  max );   // call method with actual functionality
     System . out . println ( "actual:   "   +  listArrList );   // print result
     System . out . println (( expectedResultStr . equals ( "" + listArrList )) ?   "pass"   :   "fail" );   // testing status: pass or fail
     System . out . println ();   // empty line between testing cases
   }   // end test

   //**********************************************************************

   // actual method that solve the problem

   // filterRange: eliminates any duplicates from sorted ArrayList parameter
   public   static   void  filterRange ( ArrayList < Integer >  nums ,   int  min ,   int  max )
   {
     // ADD CODE

   }   // end filterRange


}   // end class P5_EC_FilterRange