WIP

src/Sudoku.Console/Supporting Files/Node.cs

@@ -4,12 +4,12 @@ public class Node
 {
     private readonly List<Node> _children = [];
 
-    private readonly Node _parent;
-
     private readonly int[] _puzzleState = new int[81];
 
     public Move Move { get; }
 
+    public Node Parent { get; }
+
     public IReadOnlyList<Node> Children => _children;
 
     public Node(int[] puzzleState)
@@ -24,7 +24,7 @@ private Node(Move move, Node parent)
     {
         Move = move;
 
-        _parent = parent;
+        Parent = parent;
 
         for (var i = 0; i < 81; i++)
         {
@@ -36,13 +36,12 @@ private Node(Move move, Node parent)
 
     public int this[int index] => _puzzleState[index];
 
-    public void AddChild(Move child)
+    public Node AddChild(Move child)
     {
-        _children.Add(new Node(child, this));
-    }
+        var node = new Node(child, this);
+
+        _children.Add(node);
 
-    public Node Parent()
-    {
-        return _parent;
+        return node;
     }
 }

src/Sudoku.Console/TreeGenerator.cs

@@ -33,7 +33,14 @@ private void GenerateNodes(int[] puzzle, SudokuResult result)
 
         foreach (var move in result.History)
         {
+            if (move.Type == MoveType.Backtrack)
+            {
+                node = node.Parent;
+
+                continue;
+            }
 
+            node = node.AddChild(move);
         }
     }
 }