Updated Binary Tree to Include all Traversals

Traversals to be selected using enum

C#/Datastructures/BinaryTree/Tree.cs

@@ -1,5 +1,6 @@
-using C_.Datastructures.Stack;
 using C_.Datastructures.LinkedList;
+using C_.Datastructures.Stack;
+using C_.Datastructures.Queue;
 using System;
 
 namespace C_.Datastructures.BinaryTree
@@ -116,31 +117,86 @@ namespace C_.Datastructures.BinaryTree
             return true;
         }
 
-        public LinkedList<T>? Inorder()
+        public LinkedList<T>? Traverse(TraversalType traversalType)
-        {//
+        {
-            if (Count == 0)
+            if (Root == default)
                 return default;
 
             LinkedList<T> list = LinkedList<T>.Create();
 
-            Inorder(list, Root!);
+            switch (traversalType)
+            {//Select which type of traversal to do
+                case TraversalType.Inorder:
+                    Inorder(list, Root);
+                    break;
+                case TraversalType.Preorder:
+                    Preorder(list, Root);
+                    break;
+                case TraversalType.Postorder:
+                    Postorder(list, Root);
+                    break;
+                case TraversalType.Breadth:
+                    Queue<TreeNode<T>> queue = Queue<TreeNode<T>>.Create();
+                    BreadthFirst(list, queue, Root);
+                    break;
+                default:
+                    return default;
+            }
+
             return list;
         }
         private void Inorder(LinkedList<T> list, TreeNode<T> node)
-        {
+        {//Inorder Traversal
             if (node.Left != default)
                 Inorder(list, node.Left);
 
-            list.Append(node.Value!);
+            list.Append(node.Value);
 
             if (node.Right != default)
                 Inorder(list, node.Right);
         }
 
+        private void Preorder(LinkedList<T> list, TreeNode<T> node)
+        {//Preorder Traversal
+            list.Append(node.Value);
+            
+            if (node.Left != default)
+                Preorder(list, node.Left);
+
+            if (node.Right != default)
+                Preorder(list, node.Right);
+        }
+
+        private void Postorder(LinkedList<T> list, TreeNode<T> node)
+        {//Postorder Traversal
+            if (node.Left != default)
+                Postorder(list, node.Left);
+
+            if (node.Right != default)
+                Postorder(list, node.Right);
+
+            list.Append(node.Value);
+        }
+
+        private void BreadthFirst(LinkedList<T> list, Queue<TreeNode<T>> queue, TreeNode<T> node)
+        {//Breadth First Traversal
+            list.Append(node.Value);
+
+            if (node.Left != default)
+                queue.Push(node.Left);
+
+            if (node.Right != default)
+                queue.Push(node.Right);
+
+            //Only continue to traverse if there are no mode nodes to process
+            if (queue.Peek() != default)
+                BreadthFirst(list, queue, queue.Pop()!);
+        }
 
 
 
-        private TreeNode<T>? Traverse(T value, TreeNode<T>? node)
+
+        private TreeNode<T>? GetNext(T value, TreeNode<T>? node)
         {//T is comparable so use methods to determine which way to traverse
             if(node == default)
                 return default;
@@ -168,7 +224,7 @@ namespace C_.Datastructures.BinaryTree
                 if (stack.Peek()!.Value!.Equals(value))
                     return stack;
 
-                stack.Push(Traverse(value, stack.Peek()));
+                stack.Push(GetNext(value, stack.Peek()));
             }
             return default;
         }
@@ -213,7 +269,7 @@ namespace C_.Datastructures.BinaryTree
 
             TreeNode<T>? node;
 
-            node = Descend(value, Traverse(value, current));
+            node = Descend(value, GetNext(value, current));
             if (node == null)
             {
                 return current;
@@ -221,4 +277,12 @@ namespace C_.Datastructures.BinaryTree
             return node;
         }
     }
+
+    public enum TraversalType
+    {//Enum to allow for Traversal selection
+        Inorder,
+        Preorder,
+        Postorder,
+        Breadth
+    }
 }

C#/Program.cs

@@ -112,20 +112,27 @@ Console.WriteLine("Hello, World!");
 
 Tree<int> tree = new Tree<int>();
 
-tree.Add(10);
+tree.Add(40);
-tree.Add(8);
+tree.Add(30);
-tree.Add(6);
+tree.Add(50);
-tree.Add(3);
+tree.Add(25);
-tree.Add(4);
+tree.Add(35);
-tree.Add(5);
+tree.Add(45);
-tree.Add(2);
+tree.Add(60);
-tree.Add(0);
+tree.Add(15);
+tree.Add(28);
+tree.Add(55);
+tree.Add(70);
 
 
-var x = tree.Delete(10);
+//var x = tree.Delete(10);
 //tree.Delete(5);
 
-var l = tree.Inorder(null);
+var inorder = tree.Traverse(TraversalType.Inorder);
+var preorder = tree.Traverse(TraversalType.Preorder);
+var postorder = tree.Traverse(TraversalType.Postorder);
+var breadthFirst = tree.Traverse(TraversalType.Breadth);
+
 
 Console.ReadLine();