Assignment 4: Battle of Ships

Course: BBM103
Subject: File I/O, Exceptions
Assignment 4: Battle of Ships
1. Introduction
Battleship (also known as Battleships or Sea Battle) is a strategy-type guessing game for
two players. It is played on ruled grids (paper or board) on which each player’s fleet of
warships is marked. The locations of the fleets are concealed from the other player. Players
alternate turns calling “shots” at the other player’s ships, and the game’s objective is to destroy
the opposing player’s fleet.
The game is played in four grids of squares 10x10, two for each player. The individual
squares in the grids are identified by letter and number. On one grid, the player arranges
ships and records the shots by the opponent. On the other grid, the player records their shots.
Before play begins, each player secretly arranges the ships on their hidden grid. Each ship
occupies several consecutive squares on the grid, arranged either horizontally or vertically.
The type of ship determines the number of squares for each ship. The ships cannot overlap
(i.e., only one can occupy any given square in the grid). The types and numbers of ships
allowed are the same for each player. The ships should be hidden from the players’ sight, and
it is not allowed to see each other’s pieces. The game is a discovery game in which players
must discover their opponents’ positions.
BBM103 A4 1
Figure 1. A map of one player's
ships and the hits against them
from a game in progress. The
grey boxes are the ships placed
by the player, and the cross
marks show the squares their
opponent fired upon.
Rules specify the following ships:
After the ships have been positioned, the game proceeds in a series of rounds. In each
round, the current player announces a target square in the opponent's grid to shoot. The
computer announces whether or not the square is occupied by a ship, then marks the hit or
miss on the grid.
When all of the squares of a ship have been hit, the computer announces the sinking
of the Carrier, Submarine, Destroyer, Patrol Boat, or titular Battleship. If all a player's ships
have been sunk, the game is over, and their opponent wins. If all ships of both players are
sunk by the end of the round, the game is a draw. This means if Player1 bombed all ships
and Player1 has only 1 ship left you need to ask 1 more move, before prompting the final info.
2. Problem
Using a multi-dimensional built-in python list as the data structure for the grid
in the game is optional. For example, example_grid = [[“-“,”-“,”-“], [“-“,”-“,”-“], [“-“,”-
“,”-“]] represents a 3x3 initial board for the Battleship game. Necessary printing operations
can be held besides this multi-dimensional list.
Game steps:
• When the game starts, the program reads from two files (Player1.txt, Player2.txt)
which have each player’s initial selection of ship positions. For example:
No. Class of ship Size Count Label
1 Carrier 5 1 CCCCC
2 Battleship 4 2 BBBB
3 Destroyer 3 1 DDD
4 Submarine 3 1 SSS
5 Patrol Boat 2 4 PP
BBM103 A4 2
Player 2’s Board
A B C D E F G H I J
1 S
2 D C C C C C S
3 D S
4 D P P
5 B B B B
6
7 B P P
8 B P
9 B P P P
10 B
Player 1’s Board
A B C D E F G H I J
1 C
2 B C
3 P B C P P
4 P B C
5 B C
6 B B B B
7 S S S
8 D
9 P P D
10 P P D
• For the current player’s move; round count, grid size, and two grids for two of the
players and ship statuses (“-“: floating, “X”: sunk) for each player are prompted. In the
hidden boards “X” shows current hits by the opponent, “O” (big oh letter) shows the
current misses by the opponent and surrounding empty or hidden cells will remain full
of “-” characters. (In the final board, “C”, “B”, “D”, “S”, and “P” letters show stillhidden cells of unsunk ships of the winner.)
• Also, in rounds, Each user is asked for the coordinates “x, y” of the cell to bomb. In
each round, both users enters two characters separated by a comma indicating the
row (x) and column (y) indexes of the wanted cell respectively. For example: “10,D”.
To make the game easy to evaluate, current user inputs are read from the files
Player1.in and Player2.in. E.g.:
• The game repeats the previous two steps until the game finishes. When all of the
squares of a ship have been hit, the computer prints the sinking of the Carrier,
Submarine, Destroyer, Patrol Boat, or titular Battleship. If all a player’s ships have
been sunk, the game is over, and their opponent wins. If all ships of both players are
sunk by the end of the round, the game is a draw. (Outputs are: “Player1 Wins!”,
“Player2 Wins!”, “It is a Draw!”)
• Lastly, the computer prompts the final non-hidden form of the two players' boards.
BBM103 A4 3
5,E;10,G;8,I;4,C;8,F;4,F;7,A;4,A;9,C;5
,G;6,G;2,H;2,F;10,E;3,G;10,I;10,H;4,E;
8,G;2,I;4,B;5,F;2,G;10,C;10,B;2,C;3,J;
10,A;8,H;4,G;9,E;6,A;7,D;6,H;10,D;6,C;
2,J;9,B;3,E;8,E;9,I;3,F;7,F;9,D;10,J;3
,B;9,F;5,H;3,C;2,D;1,G;7,I;8,D;9,H;7,H
;5,J;6,B;4,J;4,I;3,D;8,A;2,E;4,H;1,F;1
0,F;7,B;6,I;1,I;1,E;7,G;7,J;5,C;9,G;6,
D;8,J;4,D;1,D;3,I;3,H;1,C;2,B;7,C;1,J;
� Player1.in ⤵
1,J;6,E;8,I;6,I;8,F;7,J;10,E;1,I;4,A;1
,D;7,A;10,D;2,G;8,A;5,F;5,A;5,J;1,G;6,
B;1,A;8,E;6,D;4,G;7,B;2,I;5,B;6,G;2,C;
8,D;10,I;9,G;3,F;1,F;4,H;8,J;4,J;5,C;6
,C;6,J;5,E;4,D;1,B;2,F;10,A;7,I;2,D;10
,G;7,H;6,H;9,H;7,E;9,J;3,I;3,E;7,D;9,E
;3,H;8,G;9,F;5,H;4,B;4,E;2,H;3,G;7,G;1
0,C;1,C;8,B;5,D;10,B;9,C;4,F;2,B;3,D;5
,G;9,I;3,J;7,C;7,F;2,J;10,J;3,B;2,E;
� Player2.in ⤵
;;;;;;;;;S
D;;C;C;C;C;C;;;S
D;;;;;;;;;S
D;;P;P;;;;;;
;;;;;;B;B;B;B
;;;;;;;;;
;B;;;P;P;;;;
;B;;;;;;P;;
;B;;P;P;;;P;;
;B;;;;;;;;
� Player2.txt ⤵
;;;;;;C;;;
;;;;B;;C;;;
;P;;;B;;C;P;P;
;P;;;B;;C;;;
;;;;B;;C;;;
;B;B;B;B;;;;;
;;;;;S;S;S;;
;;;;;;;;;D
;;;;P;P;;;;D
;P;P;;;;;;;D
� Player1.txt ⤵
• You may not assume the "Player1.txt", "Player2.txt", "Player1.in", and "Player2.in"
files' inputs are correctly given. You do need to check for input mistakes and
exceptions.
• When the program is executed, all the program outputs will be provided in both the
command line and the "Battleship.out" text file.
3. Exception Handling
You might have noticed that many things could go wrong with inputs and
implementation for your Battleship game. In order to prevent inconvenient cases, you will at
least handle those situations (exceptions) mentioned below.
a. IOError: A problem can occur if the input files are not reachable at the specified file
path (if files do not exist, or if their names are misspelled, etc.). Assume that your code is
executed while one or more of the input files (“Player1.txt”, “Player2.txt”, “Player1.in”,
and “Player2.in”) do not exist, you will handle it by printing the warning prompt to the
output file “IOError: input file(s) Player1.txt is/are not reachable.” or “IOError: input
file(s) Player1.txt, Player2.txt, Player1.in, Player2.in is/are not reachable.”.
d. IndexError: For missing arguments, your program should throw an index error and
handle it by giving an explanatory prompt to the user. For example, “,A;” “A;” “,;” “;”
“1,;” “1;” are some of these situations. Each situation should have a distinct message
prompt. “IndexError: <your message>”. Later, you must keep reading the same input file
until the current user can play his/her turn.
e. ValueError: If any of the first operands are given as non-numeric values, trying to
convert them to integers will raise a ValueError exception. Also, if operands are given but
you can not interpret them, you will raise the ValueError exception. For example, “A,1;”
“1,1;” “A,A;” “5,E10,G;” are some of these situations. Each situation should have a
distinct message prompt. Your code must handle this problem by printing the error
message “ValueError: <your message>”. Later, you must keep reading the same input file
until this user can play his/her turn.
b. AssertionError: If everything goes well and you get rounds for a set of user inputs, you
must assert that your result matches the game rules. If they do not match, your code
should raise an AssertionError exception and handle it by printing the error message”
AssertionError: Invalid Operation.” into the output file. Later, you must keep reading the
same input file until this current user can play his/her turn. For example: “11,A;” “5,K;”
c. Any Other Exception: You should be prepared for any other possible problem when
your code is run, as we cannot always anticipate all future problems. In case of any other
error not mentioned above, your code should print the error message” kaBOOM: run for
your life!” into the output file.
Note: Please be consider to prompt your errors into the created Battleship.out always.
BBM103 A4 4
6. What to include in the report:
• Cover (course name, assignment number, title, student number and name-surname, delivery
date)
• Analysis (describe and explain the problem in your own words,
• Design (Write your thoughts on the solution to the problem,
• for each solution/sub-solution/subroutine/function;
• write the prototype of that subroutine and explain what it does,
• write the data structures (arrays) used in that subprogram, explain their purpose,
• write the algorithm (pseudocode) of that program/subroutine.)
• Programmer's Catalogue (write down the time you spent analyzing, designing,
implementing, testing, and reporting; attach the code and explain the reusability of your
program/subprogram for other programmers, show description of possible function calls.)
• User Catalogue (program's user manual/tutorial, restrictions on the program)
Some example reports are provided as attachments.
7. Grading
In evaluating the assignment, efficiency and compliance with the structural
programming principles will be considered in addition to the correct and complete operation
of the program. It is essential to use several necessary functions because, in computer science,
it is vital to break down a problem into considerable sub-problems.
Why Do We Write Functions?
1. They allow us to conceive of our program as a bunch of sub-steps. (Each sub-step can
be its function. When any program seems too hard, break the overall program into
sub-steps!)
2. They allow us to reuse code instead of rewriting it.
3. Functions allow us to keep our variable namespace clean (local variables only "live" as
long as the function does). In other words, function_1 can use a variable called I, and
function_2 can also use a variable called I, and there is no confusion. Each variable I
only exists when the computer is executing the given function.
4. Functions allow us to test small parts of our program in isolation from the rest. This
aid is especially true in interpreted languages, such as Python and Matlab, but it can
be helpful in C, Java, and ActionScript.
Accordingly, the scoring is as follows:
Evaluation Points Evaluate Yourself / Guess Grading
Readable Codes and Meaningful Naming 5 …
Evaluation
BBM103 A4 5
5. Example Program Input/Output Scenario:
Battle of Ships Game
Player1’s Move
Round : 1 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 - - - - - - - - - - 1 - - - - - - - - - -
2 - - - - - - - - - - 2 - - - - - - - - - -
3 - - - - - - - - - - 3 - - - - - - - - - -
4 - - - - - - - - - - 4 - - - - - - - - - -
5 - - - - - - - - - - 5 - - - - - - - - - -
6 - - - - - - - - - - 6 - - - - - - - - - -
7 - - - - - - - - - - 7 - - - - - - - - - -
8 - - - - - - - - - - 8 - - - - - - - - - -
9 - - - - - - - - - - 9 - - - - - - - - - -
10- - - - - - - - - - 10- - - - - - - - - -
Carrier - Carrier -
Battleship - - Battleship - -
Destroyer - Destroyer -
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 5,E
Player2’s Move
Using Explanatory Comments 5 …
Efficiency (avoiding unnecessary actions) 5 …
Function Usage 15 …
Correctness, File I/O 30 …
Exceptions 20
Report 20 …
There are several negative evaluations … …
Evaluation Points Evaluate Yourself / Guess Grading
BBM103 A4 6
Round : 1 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 - - - - - - - - - - 1 - - - - - - - - - -
2 - - - - - - - - - - 2 - - - - - - - - - -
3 - - - - - - - - - - 3 - - - - - - - - - -
4 - - - - - - - - - - 4 - - - - - - - - - -
5 - - - - - - - - - - 5 - - - - O - - - - -
6 - - - - - - - - - - 6 - - - - - - - - - -
7 - - - - - - - - - - 7 - - - - - - - - - -
8 - - - - - - - - - - 8 - - - - - - - - - -
9 - - - - - - - - - - 9 - - - - - - - - - -
10- - - - - - - - - - 10- - - - - - - - - -
Carrier - Carrier -
Battleship - - Battleship - -
Destroyer - Destroyer -
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 1,J
Player1’s Move
Round : 2 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 - - - - - - - - - O 1 - - - - - - - - - -
2 - - - - - - - - - - 2 - - - - - - - - - -
3 - - - - - - - - - - 3 - - - - - - - - - -
4 - - - - - - - - - - 4 - - - - - - - - - -
5 - - - - - - - - - - 5 - - - - O - - - - -
6 - - - - - - - - - - 6 - - - - - - - - - -
7 - - - - - - - - - - 7 - - - - - - - - - -
8 - - - - - - - - - - 8 - - - - - - - - - -
9 - - - - - - - - - - 9 - - - - - - - - - -
10- - - - - - - - - - 10- - - - - - - - - -
Carrier - Carrier -
Battleship - - Battleship - -
Destroyer - Destroyer -
BBM103 A4 7
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 10,G
{…}
{More rounds continues… The program will print them…}
{…}
Player1’s Move
Round : 38 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 O - - O - O X - O O 1 - - - - - - - - - -
2 - - O - - - X - O - 2 - - X - - X X O O X
3 - - - - - O - - - - 3 - - - - - - O - - X
4 O - - - - - X O - O 4 X O X - O O O - - -
5 O O O - - O - - - O 5 - - - - O O X - - -
6 - X - X X - O - O - 6 O - O - - - O O - -
7 O O - - - - - - - O 7 O - - O - - - - - -
8 O - - O O O - - O X 8 - - - - - O O X O -
9 - - - - - - O - - - 9 - - O - X - - - - -
10- - - O O - - - O - 10O X O O O - O O O -
Carrier - Carrier -
Battleship - - Battleship - -
Destroyer - Destroyer -
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 9,B
Player2’s Move
Round : 38 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 O - - O - O X - O O 1 - - - - - - - - - -
2 - - O - - - X - O - 2 - - X - - X X O O X
3 - - - - - O - - - - 3 - - - - - - O - - X
BBM103 A4 8
4 O - - - - - X O - O 4 X O X - O O O - - -
5 O O O - - O - - - O 5 - - - - O O X - - -
6 - X - X X - O - O - 6 O - O - - - O O - -
7 O O - - - - - - - O 7 O - - O - - - - - -
8 O - - O O O - - O X 8 - - - - - O O X O -
9 - - - - - - O - - - 9 - X O - X - - - - -
10- - - O O - - - O - 10O X O O O - O O O -
Carrier - Carrier -
Battleship - - Battleship - -
Destroyer - Destroyer -
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 6,C
Player1’s Move
Round : 39 Grid Size: 10x10
Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 O - - O - O X - O O 1 - - - - - - - - - -
2 - - O - - - X - O - 2 - - X - - X X O O X
3 - - - - - O - - - - 3 - - - - - - O - - X
4 O - - - - - X O - O 4 X O X - O O O - - -
5 O O O - - O - - - O 5 - - - - O O X - - -
6 - X X X X - O - O - 6 O - O - - - O O - -
7 O O - - - - - - - O 7 O - - O - - - - - -
8 O - - O O O - - O X 8 - - - - - O O X O -
9 - - - - - - O - - - 9 - - O - X - - - - -
10- - - O O - - - O - 10O - O O O - O O O -
Carrier - Carrier -
Battleship X - Battleship - -
Destroyer - Destroyer -
Submarine - Submarine -
Patrol Boat - - - - Patrol Boat - - - -
Enter your move: 3,E
{…}
{More rounds continues… The program will print them…}
{…}
BBM103 A4 9
Player2’s Move
Round : 83 Grid Size: 10x10

Player1’s Hidden Board Player2’s Hidden Board
 A B C D E F G H I J A B C D E F G H I J
1 O O O O - O X - O O 1 - - O O O O O - O X
2 - O O O - O X O O O 2 - O X X X X X O O X
3 - X - O X O X X X O 3 - O O O O O O O O X
4 O X - O X O X O - O 4 X O X - O O O O O O
5 O O O O X O X O - O 5 - - O - O O X X - X
6 - X X X X - O O O O 6 O O O O - - O O O -
7 O O O O O X X X O O 7 O X O O - X O O O O
8 O O - O O O O - O X 8 O - - O O O O X O O
9 - - O - X X O O O X 9 - X O X X O O X O -
10O X X O O - O - O X 10O X O O O O O O O O
Carrier X Carrier X
Battleship X - Battleship - -
Destroyer X Destroyer -
Submarine X Submarine X
Patrol Boat X X X X Patrol Boat X X - -
Enter your move: 2,E
Player2 Wins!
Final Information
Player1’s Board Player2’s Board
 A B C D E F G H I J A B C D E F G H I J
1 O O O O - O X - O O 1 - - O O O O O - O X
2 - O O O X O X O O O 2 D O X X X X X O O X
3 - X - O X O X X X O 3 D O O O O O O O O X
4 O X - O X O X O - O 4 X O X P O O O O O O
5 O O O O X O X O - O 5 - - O - O O X X B X
6 - X X X X - O O O O 6 O O O O - - O O O -
7 O O O O O X X X O O 7 O X O O P X O O O O
8 O O - O O O O - O X 8 O B - O O O O X O O
9 - - O - X X O O O X 9 - X O X X O O X O -
10O X X O O - O - O X 10O X O O O O O O O O
BBM103 A4 10
Carrier X Carrier X
Battleship X X Battleship - -
Destroyer X Destroyer -
Submarine X Submarine X
Patrol Boat X X X X Patrol Boat X X - -
Please note that,
✓ Example input and output files are provided in the attachment for the detailed
examination. Note that punctuation and white spaces in both files are fatally
important. You may lose points because of punctuation or white spaces.
✓ If your program fails to read some of the inputs, your whole assignment could crash at
the beginning!: This indicates no grading.
✓ These long scenario round moves are randomly generated for testing purposes.
6. Notes
• Do not use input() function.
• Do not miss the submission deadline.
• Save all your work until the assignment is graded.
• The assignment must be original, individual work. Duplicates or very similar assignments
are both going to be considered cheating.. Show any references or quotes for academic
honesty.
• Write READABLE codes and their COMMENTS.
• You can ask your questions via Piazza, and you are supposed to be aware of everything
discussed on Piazza.
• You will use the online Github Classroom system to submit your work.
• No other submission method (e-mail, etc.) will be accepted. Do not submit any file via email related to this assignment.
• You need to name your assignment “Assignment4.py” and gather your work into a
single python file.
• Do not forget to fill your grading table with your expected marks and attach the table to
your report file. The report is obligatory “Assignment4.pdf ”.
• Do not hesitate to ask questions to your TA. TA’s office hours will be by appointment.
• Do not forget to write down your name and number inside both the python (as
a comment) and pdf documents.
• Before uploading, you should write, run and test your assignment in your local
environment and the dev.cs.hacettepe.edu.tr server.
BBM103 A4 11
• After 23:00(Yes, 23:01 included), we can not see your submissions; you have to submit
to the next day’s link.
• Please do not submit large files bigger than 3MB, especially for pdf sizes.
• Please do not submit the “Battleship.out” file. The output file will be created
automatically when your code is run. It will be using writing mode (not appending
mode).
• Please do not submit the “Player1.txt, Player2.txt, Player1.in, Player2.in”
files. I will provide the input files to your code within the same directory.
• Please mind that user can provide different input file names from bash.
• File hierarchy
‣ <Inside your commit without a folder>
‣ Assignment4.py
‣ Assignment4.pdf
• Sample Run
> python3 Assignment4.py "Player1.txt" "Player2.txt" "Player1.in" "Player2.in"
7. Policy
All work on assignments must be done individually unless stated otherwise. You are
encouraged to discuss with your classmates about the given assignments, but these discussions
should be carried out abstractly. Discussions about a particular solution to a problem (either
in actual code or pseudocode) will not be tolerated. In short, turning in someone else’s work
(from the internet), in whole or part, as your own will be considered a violation of academic
integrity. Please note that the former condition also holds for the material found on the web,
as everything on the web has been written by someone else.
References for the Academic Integrity (AI):
          https://academicintegrity.ucsd.edu/AI-Handbook-for-UCSD_2019.pdf,
          academicintegrity.org/resources/facts-and-statistics
BBM103 A4 12
[user@rdev ~]$ ls
Assignment4.py Assignment4.pdf Player1.txt Player2.txt Player1.in Player2.in
[user@rdev ~]$ python3 Assignment4.py "Player1.txt" "Player2.txt" "Player1.in" "Player2.in"
[user@rdev ~]$ ls
Assignment4.py Assignment4.pdf Player1.txt Player2.txt Player1.in Player2.in Battleship.out
[user@rdev ~]$
 > Assignment4.py
 > Assignment4.pdf
home/user/mycommitfiles �
Dir:apt 2 Files, total size 35.25KB