C# ISymbolicExpressionTreeNode.IterateNodesPostfix方法代码示例

 private void copySubtree() {
   if (tempNode != null) {
     foreach (var subtree in tempNode.IterateNodesPostfix()) {
       var visualNode = GetVisualSymbolicExpressionTreeNode(subtree);
       visualNode.LineColor = Color.Black;
       visualNode.TextColor = Color.Black;
       if (subtree.Parent != null) {
         var visualLine = GetVisualSymbolicExpressionTreeNodeConnection(subtree.Parent, subtree);
         visualLine.LineColor = Color.Black;
       }
     }
   }
   tempNode = currSelected.Content;
   foreach (var node in tempNode.IterateNodesPostfix()) {
     var visualNode = GetVisualSymbolicExpressionTreeNode(node);
     visualNode.LineColor = Color.LightGray;
     visualNode.TextColor = Color.LightGray;
     foreach (var subtree in node.Subtrees) {
       var visualLine = GetVisualSymbolicExpressionTreeNodeConnection(node, subtree);
       visualLine.LineColor = Color.LightGray;
     }
   }
   currSelected = null;
   RepaintNodes(); // no need to redo the layout and repaint everything since this operation does not change the tree
 }

    /// <summary>
    /// Creates a compact representation of the two trees as a directed acyclic graph
    /// </summary>
    /// <param name="n1">The root of the first tree</param>
    /// <param name="n2">The root of the second tree</param>
    /// <returns>The compacted DAG representing the two trees</returns>
    private Dictionary<ISymbolicExpressionTreeNode, GraphNode> Compact(ISymbolicExpressionTreeNode n1, ISymbolicExpressionTreeNode n2) {
      var nodeMap = new Dictionary<ISymbolicExpressionTreeNode, GraphNode>(); // K
      var labelMap = new Dictionary<string, GraphNode>(); // L
      var childrenCount = new Dictionary<ISymbolicExpressionTreeNode, int>(); // Children

      var nodes = n1.IterateNodesPostfix().Concat(n2.IterateNodesPostfix()); // the disjoint union F
      var list = new List<GraphNode>();
      var queue = new Queue<ISymbolicExpressionTreeNode>();

      foreach (var n in nodes) {
        if (n.SubtreeCount == 0) {
          var label = GetLabel(n);
          if (!labelMap.ContainsKey(label)) {
            var z = new GraphNode { SymbolicExpressionTreeNode = n, Label = label };
            labelMap[z.Label] = z;
          }
          nodeMap[n] = labelMap[label];
          queue.Enqueue(n);
        } else {
          childrenCount[n] = n.SubtreeCount;
        }
      }
      while (queue.Any()) {
        var n = queue.Dequeue();
        if (n.SubtreeCount > 0) {
          bool found = false;
          var label = n.Symbol.Name;
          var depth = n.GetDepth();

          bool sort = n.SubtreeCount > 1 && commutativeSymbols.Contains(label);
          var nSubtrees = n.Subtrees.Select(x => nodeMap[x]).ToList();
          if (sort) nSubtrees.Sort((a, b) => string.CompareOrdinal(a.Label, b.Label));

          for (int i = list.Count - 1; i >= 0; --i) {
            var w = list[i];
            if (!(n.SubtreeCount == w.SubtreeCount && label == w.Label && depth == w.Depth))
              continue;

            // sort V and W when the symbol is commutative because we are dealing with unordered trees
            var m = w.SymbolicExpressionTreeNode;
            var mSubtrees = m.Subtrees.Select(x => nodeMap[x]).ToList();
            if (sort) mSubtrees.Sort((a, b) => string.CompareOrdinal(a.Label, b.Label));

            found = nSubtrees.SequenceEqual(mSubtrees);
            if (found) {
              nodeMap[n] = w;
              break;
            }
          }

          if (!found) {
            var w = new GraphNode { SymbolicExpressionTreeNode = n, Label = label, Depth = depth };
            list.Add(w);
            nodeMap[n] = w;
          }
        }

        if (n == n1 || n == n2)
          continue;

        var p = n.Parent;
        if (p == null)
          continue;

        childrenCount[p]--;

        if (childrenCount[p] == 0)
          queue.Enqueue(p);
      }

      return nodeMap;
    }