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CS 171 - Assignment 1 (Review your Java knowledge)

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• Files used in the assignment

  This project requires the use of the following Java program files:

  "ArrayResizer.java" - Java program file used to write the methods in this project "TestA.java" - test program for Part A of assignment "TestB.java" - test program for Part B of assignment

  Download them to your PC before doing this project. (To download: right click on a link and select "Save Link As")

  Abide to the Emory Honor code when doing assignments.

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• Assignment description

  This assignment involves manipulating a two-dimensional array of integers. You will write two static methods of the ArrayResizer class, which is shown below:

  public class ArrayResizer { public static boolean isNonZeroRow( int[][] array2D, int r ) { // Write this method for part A (50 pts) return false; // Statement added to prevent compile error // Remove it when you write this method } public static int[][] resize( int[][] array2D ) { // Write this method for part B (50 pts) return null; // Statement added to prevent compile error // Remove it when you write this method } public static int numNonZeroRows( int[][] array2D ) { int numNonZeroRows = 0; for ( int i = 0; i < array2D.length; i++ ) if( isNonZeroRow( array2D, i ) ) numNonZeroRows++; return numNonZeroRows; } }

  Warning:

  If your program does not compile or crashes when the run with the provided test programs, you will receive no credit for that part of the question.

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• Part A

  Write the method isNonZeroRow(int[][] array2D, int r) , which returns true if and only if all elements in row r of a two-dimensional array array2D are not equal to zero.

  Use the provided Java program file ArrayResizer.java to write the isNonZeroRow method.
  Use the provided Java program file TestA.java to test the isNonZeroRow method.

  For example, consider the following statement, which initializes a two-dimensional array.

  int[][] arr = {{2, 1, 0}, {1, 3, 2}, {0, 0, 0}, {4, 5, 6}};

  Sample calls to isNonZeroRow are shown below:

  Call Return value Reason =========================================================================== ArrayResizer.isNonZeroRow(arr, 0) false At least one value in row 0 is zero. ArrayResizer.isNonZeroRow(arr, 1) true All values in row 1 are non-zero. ArrayResizer.isNonZeroRow(arr, 2) false At least one value in row 2 is zero. ArrayResizer.isNonZeroRow(arr, 3) true All values in row 3 are non-zero.

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• Part B

  Write the method resize(int[][] array2D), which returns a new two-dimensional array containing only rows from array2D with all non-zero values.

  The elements in the new array should appear in the same order as the order in which they appeared in the original array.

  Use the provided Java program file ArrayResizer.java to write the resize method.
  Use the provided Java program file TestB.java to test the resize method.

  Example:

  int[][] arr = {{2, 1, 0}, {1, 3, 2}, {0, 0, 0}, {4, 5, 6}}; int[][] out = ArrayResizer.resize(arr);

  When the code segment completes, the following will be the contents of out:

  {{1, 3, 2}, {4, 5, 6}}

  A helper method, numNonZeroRows(), has been provided for you. The method returns the number of rows in its two-dimensional array parameter that contain no zero values.

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• Turn in instructions

  You must be on Emory campus (e.g.: Emory unplugged) in order to turn in an assignment

  Use your web browser and visit the cs171 turnin website: click here

  Type in your NetID (in lower case) Type in your password (case sensitive !) Select Turn in assignment from the drop down Click submit Select your project file that you want to turn in Select the assignment code (for this assignment, select hw1) Click on submit If successful, you will see this message: The file ArrayResizer.java has been successfully turned in and uploaded as 0/yourNedID.hw1 If you have turned the file before, you will see this warning message Warning: the turn in has overwritten an older turn in file.

  You can turn in your program file more than once as long as you turn in before the deadline for the project.
  The turn in system will overwrite the previous turn in file with the new file that you turn in/

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• Requesting extension
  You must be on Emory campus (e.g.: Emory unplugged) in order to request extension for an assignment

  Use your web browser and visit the cs171 turnin website: click here

  Type in your NetID (in lower case) Type in your password (case sensitive !) Select Request extension from the drop down Click submit Select the assignment code (for this assignment, select hw1) Click on Req Ext If successful, you will see this message: Extension request by YourNedID for project hw1 was successfully processed The new turn in date is: "yourNedID","new-due-date" (before midnight) Please make sure your NetID and new due date was recorded correctly. Otherwise, send an email to your professor.

  If you do not see your NetID and/or a new due-date, send your professor an email - include the wrong message that you are seeing....

  You can only make one extension request per assignment.

  You have 3 "free" extension requests total.

  Additional extension requests only available for qualified circumstances with documentation (such as doctor's note for illness).