.
├── README.MD
├── main.py
├── search.py
├── state.py
└── treelib
    ├── EGG-INFO
    │   ├── PKG-INFO
    │   ├── SOURCES.txt
    │   ├── dependency_links.txt
    │   ├── top_level.txt
    │   └── zip-safe
    └── treelib
        ├── __init__.py
        ├── __init__.pyc
        ├── node.py
        ├── node.pyc
        ├── tree.py
        └── tree.pyc

All pyc files are python byte code files. The three main files for the program are the state.py, search.py, main.py

main.py

main.py will be the entry point of the program and handle input errors such as an invalid input.

search.py

search.py handles the searching for the path to the goal. Search is defined here which is a class that takes a initial string representing, a search algorithm, and a cost_flag. for a Breadth First Search a Queue is used and for all other searches a list is used. but depending on the search the list will be sorted.

state.py

state.py defines a State class which will be represent a single state of the board. Moves can be applied to a state. a state as a method that can determine if it is a goal state my counting the number of misplaced pieces. A game is completed if it has no misplaced pieces.

treelib

Treelib is a external library that handles creating and adding nodes to a tree. The search algorithm handles what gets into a tree.

The program was developed on Mac OSX Yosemite using Python. However it should run on any platform that can run Python programs in Python version 2.7.6

One of the problems I ran into was how I wanted to represent the priority queue in python. I could have imported a outside library but instead I chose to use a python list. In python the list can be treated like a stack with a pop and append function to remove and add to the top of the stack. In all Search algorithms a list is used except for the BFS because a queue is needed. To treat the list like a priority queue I sort the list while the value used to sort is our f(n) which is h(n), g(n), or h(n) + g(n). Since you want the the lowest value the list is sorted in reverse so you can pop from the list and get the lowest.

Another Problem I had was comparing classes to each other in python. in Python there is a eq() method that can be overloaded in a class. In the State class i define eq(self,other) that compares the objects strings if they are the same then return true if not return false.

python main.py [starting-board] [BFS|DFS|A-STAR|UCS|GS] [cost]

the starting board and search are required and the cost is a flag that will change the cost function to a variable cost default is constant for example to do an a-star search on a starting board wwxbb with no variable cost, the command would be

python main.py wwxbb A-STAR 

the maximum length of a starting board can be 13 that is 6 blacks and 6 whites and 1 x

I succesfully unzipped the directory and ran an example program on the school linux server for students (cs2.utdallas.edu)