🔢 N-puzzle

Solver of an N-Puzzle that uses a modified version of A*, Greedy and Uniform Cost search algorithms. You can choose between Manhattan, Hamming or Euclidean admissable heuristics.

How to use

Run using the gradle wrapper

./gradlew run

This will build the app; generate a random 3x3 puzzle (8-puzzle) and solve it using A* and Manhattan heuristic. Program args can be modified in the build.gradle:

• -a <algorithm> - one of the three algorithms
• -h <heuristic> - required for astar and greedy; forbidden for uniform
• -r <N> - optional; will genereate a N*N solvable puzzle
• -f <file path> - optional; will read the input from file
• | - optional; repeatable; gives the possibility to enter args again; will run another solver in a separate thread;
  • so ['-a astar -h manhattan -r 3 | -a astar -h euclidean -r 4'] will solve two puzzles in parallel

If no argument for the input source is provided, you will be promted to manually enter input in the following format:

3
1 2 3
4 5 6
7 8 0

Some puzzles may be unsolvable. The solution is in snail format:

1 2 3
8 0 4
7 6 5

How to test

You can run all the tests using ./gradlew test or individual tests using ./gradlew test --tests <test Class/Method>