documentation.txt

Sudoku Solver
 Solves n*n Grid where n>=3.

Algorithm
 -> In phase one, locked all  single values if any by intersecting row and columns possible values Starting with set that has lowest preemptive set.
-> If all cells are filled, then print output
-> Else try solving it by selecting a value from the subset obtained from  possiblevalueList remaining cells.
-> If solution found print it
-> Else print no Solution

P.S Most of Easy and Medium problems will be solved by first phase.

Data Structures
-> Used priority to get cell with possible values
-> A List to maintain preemptive values of each row and column
-> A Two dimensional array to store the board

Restrictions
- Only Grid with valid inputs will be allowed
- '.' should not be given in symbols list

Packages & class
* Default
  Main.java: Has main method implementation.
* Sudoku
  handler.java: Has the implementation of sudoku solution

  Methods
  * runSolver #sudoku.handler
    Does all required initialization and invokes the solution methods.

  * trySolveByLocking #sudoku.handler
    Has the implementation of locking single value.

  * tryRandomChoice #sudoku.handler
    Selects and assign a value that doesn't violate the sudoku rule from possible list to reach solution

References
1. Crook, J.F.. (2009). A pencil-and-paper algorithm for solving Sudoku puzzles. Notices of the American Mathematical Society. 56.