mutable and immutable cells

app/src/main/java/sudoku/MutableCell.java

@@ -0,0 +1,32 @@
+package sudoku;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MutableCell extends Cell{
+
+	private final List<Integer> hintsSymbolIndex;
+
+	public MutableCell() {
+		super();
+		this.hintsSymbolIndex = new ArrayList<>();
+	}
+
+	public MutableCell(int symboleIndex) {
+		super(symboleIndex);
+		this.hintsSymbolIndex = new ArrayList<>();
+	}
+
+	public void setSymboleIndex(int symboleIndex) {
+		this.symboleIndex = symboleIndex;
+	}
+
+	public void clear() {
+		setSymboleIndex(NOSYMBOLE);
+	}
+
+	public List<Integer> getHints() {
+		return this.hintsSymbolIndex;
+	}
+
+}