#A* and IDA* algorithms for 8-puzzle and 15-puzzle

requirements: python 3.5 The program can be run from the ommand line as follows:
python puzzleSolver.py <Algorithm> <N>
where,
Algorithm: 1 = A* , 2 = IDA*

N: 3 = 8-puzzle 4 = 15-puzzle format.
INPUT_FILE_PATH = The path to the input file.
OUTPUT_FILE_PATH = The path to the output file.

It would return an error if any of the command line arguments is missing or N is wrong for a given input.txt Puzzlesolver is documented in the code itself at a method level. Output files for both sample inputs 3.txt and 4.txt have been saved into 3_output.txt and 4_output.txt respectively.
PuzzleGenerator is also included for sake of easy verification.