Files structure

Each task is in the separate package (for example org.haruatari.task10) and has next files:

• The README.md markdown file with the information about what you need to do to complete the task.
• Other java classes needed to solve the task. Usually it's a Task class, but not always. See the task's description for the full information.
• The tests package which contains some tests to check your solution.

Tests

Most tasks expect that you will implement a single method. But there are tasks that need you implementing several methods or even classes (for example №8). Each of them is covered by tests. Each test checks the implemented method with several different inputs to make sure that your solution works properly with any input data.

Each test class has the public static void main(String args) method. So you can use it as the entrypoint to run only that test.

Tests for separate methods

The tests package contains a test class for each method you should implement. It has the next name: <methodName>_Test (for example Sort_Test). When you run it, it prints the next log:

====================================================================================================

Method: Point findMiddlePoint(Segment segment)
Case: A horizontal segment

Arguments:
segment: Segment(beginning: Point(x: 10; y: 10) end: Point(x: 20; y: 10))

Result:
Expected: Point(x: 15; y: 10)
Actual: null
Summary: Failed

====================================================================================================

Method: Point findMiddlePoint(Segment segment)
Case: A segment with the zero length

Arguments:
segment: Segment(beginning: Point(x: 0; y: 0) end: Point(x: 0; y: 0))

Result:
Expected: Point(x: 0; y: 0)
Actual: null
Summary: Failed

====================================================================================================

  Success:            0   
  Failed:             6   
  Success percentage: 0%   

It contains all necessary information about each case to catch an error if it exists:

• A description of the testing case
• A list of input data
• An expected result
• An actual result returned by your solution

Tests for the whole task

Each tests package contains the Test class. It runs all test in that package to check whe whole task. Its output is almost the same as method's test's but has another summary information, so you can see which of your methods failed. It also contains the whole information about tested cases.

...
====================================================================================================

| Method              | Success | Failed | Success percentage |
| int min(int[] list) | 0       | 8      | 0%                 |
| int max(int[] list) | 0       | 8      | 0%                 |
| Total               | 0       | 16     | 0%                 |

Full tests

Also, you can run all test for all tasks in a row. To do it you should run the Main class in the com.haruatari package. It will not show the detailed output, but only the summary:

| Task    | Success | Failed | Success percentage |
...
| №20 | 3       | 5      | 38%                |
| №21 | 0       | 5      | 0%                 |
| №22 | 1       | 4      | 20%                |
| №23 | 1       | 5      | 17%                |
| №24 | 0       | 4      | 0%                 |
| №25 | 0       | 7      | 0%                 |
| Total   | 24      | 135    | 15%                |

A list of tasks sorting by difficulty

Number	Name	Tags
№1	Adding and subtracting of two integers
№2	Searching by value in an array	arrays
№13	Counting of the number of occurrences of a value in an array of integers	arrays
№10	Moving the point on the coordinate plane	arrays
№8	Searching for mix and max in an array of integers	arrays
№3	Merging arrays of integers	arrays
№6	Folding of an array of integers	arrays
№11	Folding of a two-dimensional array of integers	arrays
№4	Sorting of an array of integers	algorithms, arrays
№5	Sorting of an array of objects	algorithms, arrays, objects
№12	Summation of values from an array of integers by indexes from another array	arrays
№7	Zipping of arrays of integers	arrays
№9	Searching for the middle of the segment on the coordinate plane	algorithms
№31	Calculating the distance between two points on teh coordinates plane	algorithms
№32	Calculating the total length of the broken line on the coordinate plane	algorithms, oop
№14	Calculating of a total price for the shop cart	arrays, objects
№15	Calculating of a total price for the shop cart taking discounts into account	arrays, objects
№19	Searching in the Double Linked List	objects
№16	Searching for the most popular posts on the social network. Part 1	arrays, objects
№17	Searching for the most popular posts on the social network. Part 2	arrays, objects
№18	Searching for the most popular posts on the social network. Part 3	arrays, objects
№23	Merging lists of integers	collections
№24	Folding of a list of integers	collections
№25	Folding of a nested list of integers	collections
№26	Searching for the intersection of two lists of integers	collections
№27	Searching for unique values in the list of integers	collections
№28	Pivot the map	collections
№20	Visiting a restaurant with friends. Part 1	collections, objects
№21	Visiting a restaurant with friends. Part 2	collections, objects
№22	Visiting a restaurant with friends. Part 3	collections, objects
№29	Summarizing of all integers inputted to the object	oop
№30	Factory of objects	oop
№33	Simple messenger	oop
№34 (Composite)	Changing object's behaviour by inheritance	oop
№35	Changing object's behaviour by fixing its abstract parent	oop