C# は、事前順序トラバーサル、順序内トラバーサル、事後順序トラバーサルをそれぞれ使用してバイナリ ツリーを出力します
public class BinaryTreeNode { public BinaryTreeNode Left { get; set; } public BinaryTreeNode Right { get; set; } public int Data { get; set; } public BinaryTreeNode(int data) { this.Data = data; } } public enum TreeTraversal { PREORDER, INORDER, POSTORDER } public void PrintTree(BinaryTreeNode root, TreeTraversal treeTraversal) { Action printValue = delegate(int v) { Console.Write(v + " "); }; switch (treeTraversal) { case TreeTraversal.PREORDER: PreOrderTraversal(printValue, root); break; case TreeTraversal.INORDER: InOrderTraversal(printValue, root); break; case TreeTraversal.POSTORDER: PostOrderTraversal(printValue, root); break; default: break; } } public void PreOrderTraversal(Action action, BinaryTreeNode root) { if (root == null) return; action(root.Data); PreOrderTraversal(action, root.Left); PreOrderTraversal(action, root.Right); } public void InOrderTraversal(Action action, BinaryTreeNode root) { if (root == null) return; InOrderTraversal(action, root.Left); action(root.Data); InOrderTraversal(action, root.Right); } public void PostOrderTraversal(Action action, BinaryTreeNode root) { if (root == null) return; PostOrderTraversal(action, root.Left); PostOrderTraversal(action, root.Right); action(root.Data); }