Playtech internship test assignment

This is command line java program that can solve puzzle15's with dimensions 4*4. Folder with puzzles must be provided as a command line argument. Puzzles must have .p15 extension, otherwise they are ignored.

.p15 file correct syntax

1. File can only contain numbers that are greater or equal to 0 and lesser or equal to 15.
2. Numbers are separeted with at least one whitespace.
3. File has four rows.
4. Each row has four numbers.

Output of the program

For each file with .p15 extension program prints out file name and one of the following:

1. Puzzle has correct syntax and is solvable: -turns it takes to solve this puzzle
2. The puzzle is unsolvable: -1
3. The file has incorrect syntax: -2
4. Some other unexpected error: -3

Used materials

The function that solves puzzle is based on following algorithm: https://www.instructables.com/id/How-To-Solve-The-15-Puzzle/

To check whether puzzle is solvable or not following formula was used: https://www.cs.bham.ac.uk/~mdr/teaching/modules04/java2/TilesSolvability.html