$($Name this program StuPreE$3$Select$)$ Image processing relies on multi$-$dimensional arrays. Write

a method selectRect that simulates selecting and returning a rectangular area of a $2$D image.

$//$ Returns a full $2$d int array with data from the rectangular area

$//$ specified by startRow, startCol, endRow, and endCol $($assume

$//$ startRow$<=$endRow and startCol$<=$endCol$)$ if those four indexes are

$//$ valid.

$//$ Return null if image is null or has zero rows or zero cols.

$//$ Also return null if any row$/$col index is invalid.

public static int$[][]$ selectRect$($int$[][]$ image,

int startRow, int startCol,

int endRow, int endCol$)\{$

$//$ ADD code

$\}$

Your method should return null on invalid or bad parameters as explained in the given method

prolog comment. It should also test for invalid starting$/$ending row$/$col values $($outside of valid

index ranges of the $2$D array parameter$)$ and return null. Other than those, assume

startRow$<=$endRow and startCol $<=$ endCol, that is$,$ your method only needs to handle a start

position of a top left corner to an end position of a bottom righ corner, if they are within the

ranges.

For example, given this $2$d image array $(5$ rows and $9$ cols$)$:

$012345678$

$101112131415161718$

$202122232425262728$

$303132333435363738$

$404142434445464748$

A start position $(1,2)$ to an end position $(3,7)$ would be a valid selection:

$//$ from top left corner to bottom right corner

$012345678$

$101112131415161718$

$202122232425262728$

$303132333435363738$

$404142434445464748$

For the example $2$D array, a start$/$end position of $(-1,2)$ or $(3,9)$ would be invalid.

CS$252$ Object$-$Oriented Programming

Page $3$ of $5$

Be aware that an area formed by the same start position and end position, such as $(3,5)$ ~ $(3,5)$

covers one single pixel and is still valid. That would lead to a $2$d array with one single row and

one single column.

Your main$()$ should test the method following the example below. Include at least two additional

valid cases $($besides the one shown below$)$ and one invalid case in your main$().$

int$[][]$ image $=$ new int$[][]\{$

$\{0,1,2,3,4,5,6,7,8\},$

$\{10,11,12,13,14,15,16,17,18\},$

$\{20,21,22,23,24,25,26,27,28\},$

$\{30,31,32,33,34,35,36,37,38\},$

$\{40,41,42,43,44,45,46,47,48\}$

$\}$;

System.out.println$($Arrays$.$deepToString$($image$))$; $//$ original

int startRow $=1,$ startCol $=2,$ endRow $=3,$ endCol $=7$;

int$[][]$ select; $//$ store selected area

$//($valid $1)(1,2)$ ~ $(3,7)$

select $=$ selectRect$($image$,$ startRow, startCol, endRow, endCol$)$;

System.out.printf$("(\%$d$,\%$d$)-(\%$d$,\%$d$)$: $\%$s

$",$ startRow, startCol,

endRow, endCol, Arrays.deepToString$($select$))$;

$//$ reuse variables to add additional testing cases

$...$

The above segment of code will produce this output:

$[[0,1,2,3,4,5,6,7,8],[10,11,12,13,14,15,16,17,18],$

$[20,21,22,23,24,25,26,27,28],[30,31,32,33,34,35,36,37,$

$38],[40,41,42,43,44,45,46,47,48]]$

$(1,2)-(3,7)$: $[[12,13,14,15,16,17],[22,23,24,25,26,27],$

$[32,33,34,35,36,37]]$

Arrays.deepToString$()$ is similar to Arrays.toString$()$ but works with $2$D arrays $($and

higher dimension arrays$).$ You need: import java.util.Arrays;

A downside of Arrays.deepToString$()$ is that it always returns the content in one long string. Feel

free to replace it with a method of your own to print a $2$D array in a nicer format