Week 2

In this weeks lab we will get to practice using two-dimensional arrays. We will also be using loops for doing linear searches over those same arrays and working with booleans.

Your tasks

Complete the methods in searchAndPrint.java

gridOfMultiples

This method takes as input a two-dimensional integer array. For this assignment you can assume that all rows of the array are the same length. The output will be a second two-dimensional array of the same size, this time the type will be booleans. The values of the output will correspond to the value existing in the array multiple times. This method should utlize the searchForMultiples method described below.

Here is an example: if inputArray is

[[ 4, 7, 9],
 [ 8, 9, 3]]

the output of the method would be the following boolean array:

[[false, false, true],
 [false, true, false]]

Since 9 is in the input twice, both positions in the output that correspond to those two instances are true, all of the other values only occur once, so thier values are false.

printGrid

This method takes as input a two-dimensional boolean array and prints it to the screen and stop (there is no return). The main perpose is to visualize the data for examination. Each value in the array will be printed as a _ (false) or X (true). Each row will be on its own line with no spaces between characters.

Here is an example: if inputGrid is

[[false, false, true, false],
 [false, true, false, true],
 [true, false, false, true]]

the method will print:

__X_
_X_X
X__X

searchForMutliples

This method takes as input a two-dimensional integer array, and a second scalar search integer. The output will be a single boolean that is true if the search is in the array two or more times, and false if it is in the array 0 or 1 times.

Here is an example: if search is 12 and inputArray is

[[ 12, 17, 90,  1],
 [ 12, 12, 15, 90],
 [ 16, 13, 15, 22]]

then the method would return true.

If inputArray stayed the same, but search were 17 it would return false.

Create unit tests in tester.java using Junit

You will need to create 5 unit tests for each of the methods gridOfMultiples and searchForMutliples. (Note: while you're not required to produce unit tests for printGrid, you should test it throughly.) These tests should be accompanied by pre-amble comments that describe what the test is confirming and why it is needed. The tests should be distinct from the examples provided.

Grading

100 points total

searchAndPrint.java

• 20 points for gridOfMultiples
• 10 points for printGrid
• 30 points for searchForMutliples

tester.java

• 40 points
  • 4 points for each of the 10 unit tests
    • 2 point for the test implementation
    • 2 points for the justification