package sudoku.constraint; import sudoku.structure.Sudoku; public class ColumnConstraint implements IConstraint { @Override public boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex) { for (int i = 0; i < s.getSize(); i++) { if (s.getCell(x, i).getSymbolIndex() == newSymbolIndex) return false; } return true; } }