$2800$ICT Assignment Milestone

This assignment requires you to solve problems and write software independently, and to

integrate various aspects of $C++$ programming that you have learned this trimester. You must

write ALL the C$++$ program code. This program should maximize the use of object$-$oriented

$C++$ programming.

Problem Description

Top secret agent Claude L$.$ Evers has a unique way to send encoded messages. The message

is implanted in a square grid of letters as follows: starting at the middle letter at the left$-$

most side of the grid he writes the message along the diagonal heading to the top of the

grid. After he hits the top, he then continues the message on a diagonal heading right until

he hits the right$-$hand side. He continues this way, tracing out a diamond until he reaches

the left side again. At this point he continues the message in the diamond nested inside the

diamond he just filled in$,$ and after this the next diamond inside, and so on$.$ Any leftover

squares both inside and outside the original diamond are filled with random letters.

The grids below show the steps in encoding the message $($ignoring the blank spaces$)$:

GENERAL TSO NEEDS CHICKEN NOW

The first grid shows the encoding after the first diamond has been filled in$.$ The second, third

and fourth grids show successively smaller diamonds being filled in$.$ Finally, the last grid

shows the final message after random letters have been placed in the empty squares

around the grid.

$(1)$

$(2)$

$(3)$

Note that if the original message had not filled in the entire set of diamonds, then random

letters would have been used to fill those empty slots as well $($see Sample $2$ for an example

of this when encoding GENERAL TSO HATES CHICKEN$).$ To send the message, Evers

concatenates all the rows together, top$-$to$-$bottom. The above grid would be sent as

THEESEARENSRNTAEDNCACGEEWNHLTEKOITUALNCSLYRANODOM

Now, your task is to develop a program capable of both encoding and decoding any

message.

The encoded message consists of a single string of uppercase alphabetic letters. The length

$(<mn\; id="EditorElement\_1589071">1</mn><mn\; id="EditorElement\_1589072">0</mn><mn\; id="EditorElement\_1589073">0</mn><mn\; id="EditorElement\_1589074">0</mn><mi\; id="EditorElement\_1589075">)</mi>$ of the encoded message will be a square of an odd integer. Note that the decoded

message might contain some random letters at the end if the original message did not fill

the entire set of diamonds. Some encoded and its decoded messages are like below:

Sample $1,$

Encoded: THEESEARENSRNTAEDNCACGEEWNHLTEKOITUALNCSLYRANODOM

Decoded: GENERALTSONEEDSCHICKENNOW

Sample $2,$

Encoded: WHAETHERENSRALLEENCAYGTELIHLKAKEITSARHCSEBIGMOACS

Decoded: GENERALTSOHATESCHICKENIEL

Sample $3,$

Encoded: JOMHNPARTAILUUHLASERINWGO

Requirements:

Your task is to develop an object$-$oriented C$++$ program with a textual user interface like

below. After running each option, the interface should display after its output.

This program can always continue, even if a user enters incorrect data, until the user

quit it$.$ This means that the system should be able to handle various exceptions that

may occur during execution.

For option $2$ and $5,$ allow the user to enter a file name or use a default file name.

For option $3,$ when developing the encoding scheme, provide two ways for setting

the size of the square grid:

o one is to allow the user to enter the grid size,

one is to let the program to decide a suitable size for the square grid. Note

that there may be multiple suitable sizes for the square grid.

For option $4,$ your task is to implement the decoding scheme. Your program should

accurately decode the encoded messages provided in Sample $1$ through Sample $3.$

Produce a UML for each class used in your program. Each UML must clearly identify:

The name of the class

The name and data type of each member variable

For each member function

Its name

Its return data type

For each parameter: its name and data type

All member variables and functions should clearly show their visibility $($i$.$e$.$

private$(-)/$public$(+)/$protected$($#$))$

Inheritance relationship if applicable

Be well written $($sensible variable names, indentation, no too long functions,

appropriate comments$)$ Submit:

$1,$ all C$++$ source code: $*.$cpp and $*.$hpp if your code is organized into separate files.

$2,$ week$11.$txt: a txt file contains all the source code.

$3,$ week$11.$docx or week$11.$pdf$,$ this document should include:

UML for each class

Screenshot for running each option in the textual user interface, including normal and abnormal inputs. For example, the normal and abnormal inputs are like below:

$\backslash$table$[[$#option,Normal Input,Abnormal Input$],[1,$A message,Empty input$],[2,$File name,$\backslash$table$[[$Wrong file name$]]],[3,\backslash$table$[[$A$],[$message$]],\backslash$table$[[$Grid size by user$]],$Empty message input$],[$Grid size by program,Grid size by user but not a number$],[4,$The three samples,$\backslash$table$[[$The length of the encoded message$],[$is not a square of an odd integer.$]]],[5,$File name,Empty input$],[6,$Desired character,Not desired character$]]$

Please refer to the submission page for the Marking Rubric.