Put it all together to read in the data from file, spawn four threads, and allocate the task of summing each quadrant pair to a separate thread.

After the threads complete their computation, the results need to be stored in the matrix C$,$ another $2-$dimensional array variable in main.

$$

Your program should work for any size matrices.

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In ThreadOperation write a method named getQuadrantIndexes that determines the indexes needed to iterate over one of the four quadrants. For instance, your method might take as input the row count, column count, and a quadrant String, and then return $4$ numbers in an array: row start, row end, column start, column end. Although I$$m demonstrating this method using a String to indicate the quadrant, an integer would also work fine, and an enum with four values would be best.

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public static int$[]$ getQuadrantIndexes$($int rows, int columns, String quadrant$)$

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Called as int$[]$ indexes $=$ getQuadrantIndexes$($rows$,$ columns, $$upper left$)$;

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There are many different $($and some better$)$ ways to get the indexes, but this is the way that I think will make sense to the most people.

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So how do you actually calculate the indexes needed? You will need four conditions $($if$,$ elseif, elseif, else$)$ for the four quadrants. Figure out the pattern based on the following examples:

Example $1$

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$6$ columns

$8$ rows

Row indexes from $0$ to $3$

Column indexes from $0$ to $2$

Row indexes from $0$ to $3$

Column indexes from $3$ to $5$

Row indexes from $4$ to $7$

Column indexes from $0$ to $2$

Row indexes from $4$ to $7$

Column indexes from $3$ to $5$

Example $2$

$$

$12$ columns

$7$ rows

Row indexes from $0$ to $2$

Column indexes from $0$ to $5$

Row indexes from $0$ to $2$

Column indexes from $6$ to $11$

Row indexes from $3$ to $6$

Column indexes from $0$ to $5$

Row indexes from $3$ to $6$

Column indexes from $6$ to $11$

$$

Example $3$

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$5$ columns

$9$ rows

Row indexes from $0$ to $3$

Column indexes from $0$ to $1$

Row indexes from $0$ to $3$

Column indexes from $2$ to $4$

Row indexes from $4$ to $8$

Column indexes from $0$ to $1$

Row indexes from $4$ to $8$

Column indexes from $2$ to $4$

$$

Example $4$ Fill$-$in$-$the$-$blanks

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C columns

R rows

Row indexes from $0$ to $\_\_\_\_\_$

Column indexes from $0$ to $\_\_\_\_\_$

Row indexes from $0$ to $\_\_\_\_\_$

Column indexes from $\_\_\_\_\_$ to $\_\_\_\_\_$

Row indexes from $\_\_\_\_\_$ to $\_\_\_\_\_$

Column indexes from $0$ to $\_\_\_\_\_$

Row indexes from $\_\_\_\_\_$ to $\_\_\_\_\_$

Column indexes from $\_\_\_\_\_$ to $\_\_\_\_\_$

$$

Main.java should be organized as follows $($Strongly consider using the following notes as comments$)$:

$$ Your main method opens a text file using the file name from the command line, and reads in the number of rows, the number of columns, and two matrices, A and B$,$ into two $2-$dimensional array variables.

$$ Instantiate four ThreadOperation objects and pass them the information they need to sum up paired quadrants, including a reference to a result matrix C$.$ Note that C should have the same dimensions as A and B$.$

$$ Start up all the threads and use join to make sure they finish before printing.

$$ Print out the summed matrix.

$$

ThreadOperation.java Organization

I recommend formatting the ThreadOperation constructor as follows:

$<>$ThreadOperation$($A : int$[][],$ B : int$[][],$ C : int$[][],$ String quadrant$)$

run$()$ : void

$$

A$,$ B$,$ and C all refer to complete matrices $($no sub$-$matrices$)$ of the same size. As long as the Thread is not accessing the same row and column as another Thread, there$$s no problem!

UML Diagram for Matrix Addition Part $2$

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You tell me$!$

$$

For part $2$ you must turn in a UML diagram of your code, including the ways you modified Main and ThreadOperation to complete the assignment.

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Compilation and Execution

I will test your program as follows:

$$ javac $*.$java

$$ java Main matrix$1.$txt

or

$$ java Main matrix$2.$txt

or

$$ java Main matrix$3.$txt

Using this as a BASE

$/$import java.io$.$IOException;

import java.io$.$File;

import java.util.Scanner;

public class Main $\{$

public static void main$($String$[]$ args$)\{$

if $($args$.$length $!=1)\{$

System.out.println$("$Usage: java Main