Minor, traversal order explained.

Author: Clément

source/code/projects/Tree/Tree/BSTree.cs

@@ -57,6 +57,8 @@ private bool Delete(T dataP, ref Node nodeP)
         {
           nodeP.Data = FindMin(nodeP.right);
           Delete(nodeP.Data, ref nodeP.right);
+                    // Or we could replace with the largest
+                    // value in the left subtree.
         }
         else
         {

source/code/projects/Tree/Tree/BTree.cs

@@ -112,81 +112,83 @@ private bool Find(Node nodeP, T dataP)
 
     // Done with finding.
 
-  public abstract void Insert(T dataP);
-  public abstract bool Delete(T dataP);
-
-  /* Traversal methods. */
-  // Inorder traversal
-  // "Left, root, right"
-  public string TrasverseI()
-  {
-    string returned = "";
-    if (root != null)
+    /* Traversal methods. */
+    // Inorder traversal
+    // "Left, root, right"
+    public string TrasverseI()
     {
-      returned += TraverseI(root);
+        string returned = "";
+        if (root != null)
+        {
+            returned += TraverseI(root);
+        }
+        return returned;
     }
-    return returned;
-  }
 
-  private string TraverseI(Node nodeP)
-  {
-    string returned = "";
-    if (nodeP != null)
+    private string TraverseI(Node nodeP)
     {
-      returned += TraverseI(nodeP.left);
-      returned += nodeP.Data + " ";
-      returned += TraverseI(nodeP.right);
+        string returned = "";
+        if (nodeP != null)
+        {
+            returned += TraverseI(nodeP.left);
+            returned += nodeP.Data + " ";
+            returned += TraverseI(nodeP.right);
+        }
+        return returned;
     }
-    return returned;
-  }
 
-  // Preorder traversal
-  // "Root, left, right"
-  public string TrasversePr()
-  {
-    string returned = "";
-    if (root != null)
+    // Preorder traversal
+    // "Root, left, right"
+    public string TrasversePr()
     {
-      returned += TraversePr(root);
+        string returned = "";
+        if (root != null)
+        {
+            returned += TraversePr(root);
+        }
+        return returned;
     }
-    return returned;
-  }
 
-  private string TraversePr(Node nodeP)
-  {
-    string returned = "";
-    if (nodeP != null)
+    private string TraversePr(Node nodeP)
     {
-      returned += nodeP.Data + " ";
-      returned += TraversePr(nodeP.left);
-      returned += TraversePr(nodeP.right);
+        string returned = "";
+        if (nodeP != null)
+        {
+            returned += nodeP.Data + " ";
+            returned += TraversePr(nodeP.left);
+            returned += TraversePr(nodeP.right);
+        }
+        return returned;
     }
-    return returned;
-  }
 
-  // Postorder traversal
-  // "Left, right, root"
-  public string TrasversePo()
-  {
-    string returned = "";
-    if (root != null)
+    // Postorder traversal
+    // "Left, right, root"
+    public string TrasversePo()
     {
-      returned += TraversePo(root);
+        string returned = "";
+        if (root != null)
+        {
+            returned += TraversePo(root);
+        }
+        return returned;
     }
-    return returned;
-  }
 
-  private string TraversePo(Node nodeP)
-  {
-    string returned = "";
-    if (nodeP != null)
+    private string TraversePo(Node nodeP)
     {
-      returned += TraversePo(nodeP.left);
-      returned += TraversePo(nodeP.right);
-      returned += nodeP.Data + " ";
+        string returned = "";
+        if (nodeP != null)
+        {
+            returned += TraversePo(nodeP.left);
+            returned += TraversePo(nodeP.right);
+            returned += nodeP.Data + " ";
+        }
+        return returned;
     }
-    return returned;
-  }
+
+    public abstract void Insert(T dataP);
+  public abstract bool Delete(T dataP);
+
+  
 
 
     // The ToString method is simply here to help debug.

source/lectures/data/trees.md

@@ -92,6 +92,13 @@ Etc., etc. Hence, we get:
 
 #### Displaying Trees
 
+There are essentially three ways of "linearizing" a tree (that is, listing its value as a list):
+
+```{download="./code/projects/Tree.zip"}
+!include`snippetStart="/* Traversal methods. */", snippetEnd="/* Done with traversal methods. */"` code/projects/Tree/Tree/BTree.cs
+```
+
+
 #### Implementation Detail
 
 We implemented the binary tree class abstractly, because two methods are still missing: how to insert a value, and how to delete a value (we will add them later on).