Homeworks for "Java Programming" course

Task 1. Image processing.

Your task is to implement methods: impl.image.ImageConverterImpl.convertToColor, impl.image.ImageConverterImpl.convertToRgb and impl.image.ConvolutionProviderImpl.apply. You should write an implementation where TODO is written.

Method impl.image.ImageConverterImpl.convertToColor should transform int[][] to Color[][], method impl.image.ImageConverterImpl.convertToRgb should transform Color[][] to int[][]. Where int contains information about color this way:

0-7 bits contain info about blue color,
8-15 bits contain info about green color,
16-23 bits contain info about red color,
24-31 bits contains info about a transparency (alpha layer).

impl.image.ConvolutionProviderImpl.apply should apply convolution operation on given image, using given kernel (guaranteed that kernel dimensions are > 0).

You should apply convolution operation for each color separately.
Image dimensions shouldn't be changed.
If during convolution operation, the core element goes beyond the picture, it should be considered that red, green, blue = 0.
alpha should be always 255.
After each multiplication of the color value by the kernel element, result should be rounded to 0.

If you want to experiment with other cores you can use class ImageUtil it contains methods writeOutputImage, readOriginImage which allows reading images from resources/image/origin folder and writing images to resources/image/output folder. Using them you can watch how the convolution operation affects images.

All pictures must be in the png format.
When you specify the name of the image, the format should also be indicated (e.g. pic1.png).

Task 2. Exceptions

Your task is to implement methods: impl.expression.ExpressionParserImpl.parse. You should write an implementation where TODO is written.

ExpressionParser should calculate arithmetic expression expression.

expression contains integer constants, +, - and whitespaces.

All calculations should be done using int.
There can be no whitespace inside constants.
Several +, - cannot be in a row.
Expression parsing should work in linear time.

Pay attention to the processing of possible parsing and calculation errors.

Task 3. Queue

Your task is to implement the interface api.queue.IntQueue in two different ways: using array and using linked list. Create implemented instances in methods impl.queue.ArrayQueueFactory.getInstance and impl.queue.LinkedQueueFactory.getInstance.

The use of Java Collections framework is prohibited.

Note the extraction of the common code.

Task 4. Year weather stats

Your task is to implement the interfaces api.weather.DayTemperatureInfoParser and api.weather.YearTemperatureStats. Create implemented instances in methods impl.weather.DayTemperatureInfoParserFactory.getInstance and impl.weather.YearTemperatureStatsFactory.getInstance.

YearTemperatureStats should be able to return information about:

temperature of the given day (null if info about this day isn't known); [return it in constant time]
average temperature for the given month (null if info about this month isn't known); [return it in constant time]
maximal temperature for each known month; [return it in O(known months count) time]
list of DayTemperatureInfo for the given month. This list should be sorted in ascending order. If some days had the same temperature then they should be sorted by the insertion order.

YearTemperatureStats should be able to update its state using given DayTemperatureInfo [in constant time].

DayTemperatureInfoParser should be able to create DayTemperatureInfo from the raw String. You can assume that this String has the following format: day.month temperature.

Task 5. Files

Your task is to implement the interfaces api.file.FileEncodingReader and api.file.FileEncodingWriter. Create implemented instances in methods impl.file.FileEncodingReaderFactory.getInstance and impl.file.FileEncodingWriterFactory.getInstance.

FileEncodingReader should create java.io.Reader from the given file with the specific charset.