package sudoku.constraint; import sudoku.structure.Cell; 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++) { Cell cell = s.getCell(x, i); int symbol = cell.getSymbolIndex(); if (symbol == newSymbolIndex) { return false; } } return true; } }