feat : Solver.solve()

app/src/main/java/sudoku/Sudoku.java

@@ -162,4 +162,31 @@ public class Sudoku {
 		sb.append("\n}");
 		return sb.toString();
 	}
+
+	public MutableCell getFirstEmptyMutableCell() {
+		for (MutableCell cell : this.getMutableCells()) {
+			if (cell.isEmpty()) {
+				return cell;
+			}
+		}
+		return null;
+	}
+
+	public List<Integer> getPossibleSymbolsOfCell(MutableCell cellToFill) {
+		List<Integer> result = new ArrayList<>();
+		Coordinate cellCoordinates;
+		try {
+			cellCoordinates = this.getCoordinateCell(cellToFill);
+		} catch (Exception e) {
+			return result;
+		}
+		for (IConstraint constraint : this.constraints) {
+			if (result.isEmpty()) {
+				result.addAll(constraint.getPossibleSymbols(this, cellCoordinates.getX(), cellCoordinates.getY()));
+			} else {
+				result.retainAll(constraint.getPossibleSymbols(this, cellCoordinates.getX(), cellCoordinates.getY()));
+			}
+		}
+		return result;
+	}
 }