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When your reduceBoard() method is working, clicking the Reduce button will perform a single pass reduction on every cell on the board. You should thus be able to progress towards a solution by repeatedly clicking the Reduce button, though you might end up with either an unsolvable or irreducible board. Attempting to reduce an unsolvable or irreducible board will have no effect on the board.
Finding Find a Minimum Choice Cell
When your findMinChoiceCell() method is working, clicking the Find Min Choice Cell button will pop up a message dialog box displaying the contents of the chosen cell. It does not show the location of the cell because that information is not available. Which cell is chosen depends on the heuristic used. One can manually attempt to solve an irreducible board by getting the values of the cell to be replaced and removing all values except one from the selected cell and then trying to further reduce the cell.
Solve the Board
Once your solve() method is working, clicking the Solve button will attempt to solve the board from its current configuration.Solving the Board
Generating Solvable Puzzles
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