- Java version is in (Eclipse) project
judoku. - Scala port is in (Eclipse) project
scudoku. Port is 90% identical to the Java version except for some optimizations and minor refactorings. Algorithms are Scala-style!
Main class is scudoku.SudokuSolver which calls various solving algorithms one after another until the grid does not change anymore.
Besides the SudokuSolver also calls the consistency checks to find out if we ran into an inconsistent situation.
Data structures are in judoku|scudoku.data:
scudoku.data.Gridis the sudoku grid, containing 81 = 9x9 cellsscudoku.data.Lineis one of the 9 lines (= rows) in the gridscudoku.data.Columnis one of the 9 columns in the gridscudoku.data.Blockis one of the 9 (3x3) blocks in the grid
Each of the 81 scudoku.data.Cells has a value (in case its vallue is fix) or a set of potential values which are eliminated one by one.
Changes to a scudoku.data.Cell are observed by the scudoku.data.Grid (and other observers) to react on the change.
The enumeration scudoku.data.UnknownOneToNine is an enumeration of 1,2,...,9 and 'Unknown' for the list of potential values of a cell.
Solvers are different algorithms which try to either fix a value in a cell by deleting potential values:
scudoku.solvers.OnlyOnePotentialValueLeftInCell: If no more potential values in a cell => Fix its valuescudoku.solvers.LastPotentialValueInBlockOrLineOrColumn: If only one cell has a potential value (in a block/line/column) => Fix its valuescudoku.solvers.IfValueFixedToLineOrColumnInsideABlockThenDeleteFromRest: If we know that one line/column of a block can contain an potential values => Delete it from the rest of the line/column in the other blocks
Checkers do consistency checks on the grid:
scudoku.checkers.CheckCellsForFixDuplicateValues: If two or more cells (in a line/column/block) have the same fix value, then we are doomed.scudoku.checkers.CheckCellsForNoMorePotentialValuesAvailable: Any cell which is not fix but does not have any more potential values? Then we are also doomed.