The Background

Autofill in paint uses a recursive algorithm to "spread" the paint to pixels of the same color. Looking at the example below, the "fill" tool is in the middle of the A, when clicking the tool ONCE, it fills in the rest of the area that is in white.

Notice that the fill did NOT extend into the black (or non-white) colored pixels or beyond the borders. Any non-white colored pixel within borders is a natural barrier that does not allow the fill to spread. Notice if there is a "crack" in the design like in the example below, it will spread beyond, but still does not fill in the natural barrier.

If there is any white space connected to the original location to fill, it will be changed. Autofill looks at locations UP, DOWN, LEFT and RIGHT from the original spot, and continues the spreading action in the next pixel.

The Picture File

The "Picture" file is no more than a text file with .'s and x's. The .'s are the white spaces, while the x's are the natural borders. (x's cannot be changed). Here is a sample below:

.....xx........
....x..xx......
....x....xxxx..
...x........xxx
..x............
...x........xx.
...x..xxx...x.x
...x..x..x.x...
...xxxx...x....
...............

Here is a sample of the picture file. matrix1.txt

As a programmer, you will:

NOT know the size of the text file (rows and columns)
be required to use a try/catch in order to check to see if the file is present

The Task

Your assignment will be to autofill a given "picture" when the user gives the file name of the "picture file", row and column to start the fill. The program will display the picture BEFORE the autofill and display and write the results after the autofill.

Program Requirements

use command line arguments. At the command line the user must enter (in this order):
- the name of the executable file (e.g. proj1.py),
- the name of the picture file
- row coordinate to start the fill.
- column coordinate to start the fill.

python proj2.py matrix1.txt 0 0

Using a try/catch, determine if the file is present. If not, exit the program. (You will need to reserach this!!)
Display the content of the picture file to the screen in a box (matrix) form
use a RECURSIVE autofill function to fill all items that are not filled. Iterative versions will receive no credit.
write the results to the SCREEN and FILE.

the results file will be created using the file name entered at command line:

(at command line): matrix1.txt
(result file name): matrix1-results.txt

close any files that you have opened as soon as you have finished using them.

Sample Run

Here is a sample of output of this program. Please note that the sample output only shows what is expected from your program if the user is actually entering everything as instructed. This is not a test of the program at all, but just a sample for your clarification.

Matrix BEFORE Autofill
.....xx........
....x..xx......
....x....xxxx..
...x........xxx
..x............
...x........xx.
...x..xxx...x.x
...x..x..x.x...
...xxxx...x....
...............

Matrix AFTER autofill, starting a location 0,0
xxxxxxx........
xxxxx..xx......
xxxxx....xxxx..
xxxx........xxx
xxx............
xxxx........xx.
xxxx..xxx...xxx
xxxx..xxxx.xxxx
xxxxxxxxxxxxxxx
xxxxxxxxxxxxxxx

Extra Credit

Allow other SINGLE characters as the fill. (OTHER than 'x'.) You must specify the character in the last spot in your command line. Also, in this extra credit, whatever coordinate is given, it will use that character as the character to be filled.
Example 1

python proj2.py matrix3.txt 6 12 Y

Matrix BEFORE autofill
.......................
.............*.........
............***........
...........*.**........
..........*..**........
.........*....**.......
........*.....**.......
.......**********......
......*........**......
.....*..........**.....
....**..........***....
..*****........*****...
.......................

Matrix AFTER autofill, starting at location 6, 12
.......................
.............*.........
............***........
...........*Y**........
..........*YY**........
.........*YYYY**.......
........*YYYYY**.......
.......**********......
......*........**......
.....*..........**.....
....**..........***....
..*****........*****...
.......................

Example 2

python proj2.py matrix4.txt 6 12 Y

Matrix BEFORE autofill
_______________________
_____________*_________
____________***________
___________*_**________
__________*__**________
_________*____**_______
________*_____**_______
_______**********______
______*________**______
_____*__________**_____
____**__________***____
__*****________*****___
_______________________

Matrix AFTER autofill, starting at location 6, 12
_______________________
_____________*_________
____________***________
___________*Y**________
__________*YY**________
_________*YYYY**_______
________*YYYYY**_______
_______**********______
______*________**______
_____*__________**_____
____**__________***____
__*****________*****___
_______________________

Example 3

python proj2.py matrix3.txt 2 13 A

Matrix BEFORE autofill
.......................
.............*.........
............***........
...........*.**........
..........*..**........
.........*....**.......
........*.....**.......
.......**********......
......*........**......
.....*..........**.....
....**..........***....
..*****........*****...
.......................

Matrix AFTER autofill, starting at location 2, 13
.......................
.............A.........
............AAA........
...........*.AA........
..........*..AA........
.........*....AA.......
........A.....AA.......
.......AAAAAAAAAA......
......*........AA......
.....*..........AA.....
....**..........AAA....
..*****........AAAAA...
.......................

Submitting your work

You must be logged into your account and in the same directory as the file you are trying to submit.

To submit your design, type the following at the linux prompt:

submit cs201 Proj2 design2.txt

To submit your project, type the following at the linux prompt:

submit cs201 Proj2 proj2.py

To verify that your files were submitted, you can execute the following command at the Unix prompt. It will show all files that you submitted in a format similar to the Unix 'ls' command.

submitls cs201 Proj2

Project 2 - Autofill