This is a re-write of the final project of CS 171: Intro to Artificial Intelligence at UCI. MSS is written in C++11.

This will generate puzzles randomly, or from text files, and solve puzzles. This will also log and keep track of statistics- time taken by individual algorithms, nodes searched, dead ends, etc.

This also has a number of heuristic algorithms that can be enabled or disabled. This is purely to experiment- see what combination of heuristics performs the best over different sized puzzles. The heuristics are as follows:

• Minimum remaining values

• Least constraining value

• Max degrees

• Arc consistency check

• Forward check

The generator generates a random sudoku puzzle based on four integers: m, n, p, q. The puzzle is not guaranteed to be solvable, nor to have a unique solution. It only guarantees that the initially solved cells are all legal.

• m: m is the number of clues, or initially solved cells. m should be at least 1 (else the puzzle is easily solvable and is of no use), and should be less than n^2 (else the puzzle is already solved and is of no use). Be careful with m, as having it too low compared to n^2 will cause the puzzle to have multiple solutions, and having it too high will cause the generator to potentially timeout. For the standard 9x9 puzzle, m = 17 is the minimum number of clues for a puzzle to have a unique solution.

• n: n is the size of the puzzle. The standard size for a sudoku puzzle is n = 9. Note that larger n's will generate larger puzzles, and thus, will take much longer to solve.

• p: p is the height of each block. The product p * q must equal n. This is a requirement of a sudoku puzzle.

• q: q is the width of each block.

The solver will use backtracking search and the enabled heuristics to solve the given puzzle.

The input file is expected to be in a specific format:

• The first line must have four numbers, delimited by a single space. These are the m, n, p, q parameters.

• Then it expects n lines, each with n characters. Denote empty cells with '.' and solved cells with the respective value.

• For n <= 9 puzzles, the characters should be 1 - 9. For anything higher (up to 35), use capital letters with A being 10, B being 11, etc.

• You can put extra lines after, but those will be ignored. Same with extra characters after the first n per line (except the first).

-Except for the first line, DO NOT put spaces in between characters.

1. Download the MonsterSudoku folder.

2. To compile, run g++ -std=c++11 -static -o main with all of the source files. You can name the -o any name you wish.

3. Run the .o you just created: ./main (or whatever you named the .o).

4. The program runs in a loop. You enter commands to either generate or solve. Type "help" to see how to use the commands.

To generate a puzzle: gen m n p q file_path. This will generate a random puzzle based on the m, n, p, q parameters and save it to a text file at file_path.

To solve a puzzle: solve file_path [optional arguments]. This will load up a puzzle from the file_path and solve it. Alternatively, you can also do solve -g m n p q [optional arguments]. This will first randomly generate a puzzle based on the m, n, p, q parameters , and then solve it.

When solving a puzzle, you can set various options. These are:

• -v: After solving the puzzle, or experiencing a timeout, it will display a report displaying the time taken by each heuristic and algorithm, # of nodes, # of dead ends, etc.

• -u: Will also display the current puzzle state after each assignment and backtrack.

• -p: Used with -u, it will pause the solving after each assignment and backtrack until an input is received.

• -s: Used with -u, it will add a delay after each display.

• -all: Use all heuristics to solve the puzzle.

• -mrv: Enable the mrv heuristic.

• -md: Enable the md heuristic.

• -lcv: Enable the lcv heuristic.

• -acp: Enable arc consistency-3 check as a pre-processor.

• -mac: Enable arc consistency-3 check after each assignment.

• -fc: Enable forward check after each assignment.

• -do: Only enable the dynamic ordering heuristics: mrv, md, lcv.

• -cp: Only enable th arc consistency-3 checks and forward checks.