Iterative traversal method (#13)

Author: goodyear-incaricotech

DStruct/BinaryTrees/AVLTree.cs

@@ -1,4 +1,5 @@
-using System;
+using DStruct.Queues;
+using System;
 using System.Collections.Generic;
 
 // ReSharper disable RedundantAssignment
@@ -7,93 +8,10 @@ namespace DStruct.BinaryTrees
 {
     /// <summary>Represents a node-based, self-balancing <see cref="IBinarySearchTree{T}"/> enhanced to implement an efficient indexer.</summary>
     /// <typeparam name="T">The type of the values stored in the <see cref="AVLTree{T}"/>.</typeparam>
-    public class AVLTree<T> : IBinarySearchTree<T>
+    public class AVLTree<T> : BinarySearchTreeBase<T>
     {
-        private readonly IComparer<T> _comparer = Comparer<T>.Default;
-
         private AVLTreeNode<T> _root;
 
-        /// <summary>Gets the number of elements stored in the <see cref="AVLTree{T}" />. <code>Complexity: O(1)</code></summary>
-        public int Count { get; private set; }
-
-        /// <summary>Gets the minimum value element stored in the <see cref="AVLTree{T}"/>. <code>Complexity: O(LogN)</code></summary>
-        /// <exception cref="InvalidOperationException"><see cref="AVLTree{T}"/> is empty.</exception>
-        public T Min
-        {
-            get
-            {
-                if (_root == null)
-                {
-                    throw new InvalidOperationException("The AVLTree is empty.");
-                }
-
-                var curr = _root;
-                while (curr.Left != null)
-                {
-                    curr = curr.Left;
-                }
-
-                return curr.Value;
-            }
-        }
-
-        /// <summary>Gets the maximum value element stored in the <see cref="AVLTree{T}" />. <code>Complexity: O(LogN)</code></summary>
-        /// <exception cref="InvalidOperationException"><see cref="AVLTree{T}"/> is empty.</exception>
-        public T Max
-        {
-            get
-            {
-                if (_root == null)
-                {
-                    throw new InvalidOperationException("The AVLTree is empty.");
-                }
-
-                var curr = _root;
-                while (curr.Right != null)
-                {
-                    curr = curr.Right;
-                }
-
-                return curr.Value;
-            }
-        }
-
-        /// <summary>Gets the element at the specified index. <code>Complexity: O(LogN)</code></summary>
-        /// <param name="index">The index of the element to get from the <see cref="AVLTree{T}"/>.</param>
-        /// <returns>The element at the specified index.</returns>
-        /// <exception cref="IndexOutOfRangeException"><paramref name="index"/> is out of the bounds of the <see cref="AVLTree{T}"/>.</exception>
-        public T this[int index]
-        {
-            get
-            {
-                if (index < 0 || index >= Count)
-                {
-                    throw new IndexOutOfRangeException("Index is outside the bounds of the AVLTree.");
-                }
-
-                var curr  = _root;
-                int check = 0;
-
-                while (true)
-                {
-                    if (check + curr.LeftChildren == index)
-                    {
-                        return curr.Value;
-                    }
-
-                    if (check + curr.LeftChildren > index)
-                    {
-                        curr = curr.Left;
-                    }
-                    else
-                    {
-                        check += curr.LeftChildren + 1;
-                        curr  =  curr.Right;
-                    }
-                }
-            }
-        }
-
         /// <summary>Initializes a new instance of <see cref="AVLTree{T}"/> that is empty.</summary>
         public AVLTree()
         {
@@ -103,30 +21,24 @@ public AVLTree()
         /// <param name="collection">The collection of elements to add to the <see cref="AVLTree{T}"/>.</param>
         /// <exception cref="ArgumentNullException"><paramref name="collection"/> is <c>null</c>.</exception>
         public AVLTree(IEnumerable<T> collection)
+            : base(collection)
         {
-            if (collection == null)
-            {
-                throw new ArgumentNullException(nameof(collection));
-            }
-
-            foreach (var value in collection)
-            {
-                Insert(value);
-            }
         }
 
         /// <summary>Initializes a new instance of <see cref="AVLTree{T}"/> that is empty and uses the specified <see cref="IComparer{T}"/>.</summary>
         /// <param name="comparer">The <see cref="IComparer{T}"/> that will be used for making comparisons.</param>
         /// <exception cref="ArgumentNullException"><paramref name="comparer"/> is <c>null</c>.</exception>
         public AVLTree(IComparer<T> comparer)
+            : base(comparer)
         {
-            _comparer = comparer ?? throw new ArgumentNullException(nameof(comparer));
         }
 
+        private protected override IBinarySearchTreeNode<T> Root => _root;
+
         /// <summary>Inserts an element into the <see cref="AVLTree{T}" /> and returns its index. <code>Complexity: O(LogN)</code></summary>
         /// <param name="value">The element to add to the <see cref="AVLTree{T}"/>.</param>
         /// <returns>The index at which the element was placed.</returns>
-        public int Insert(T value)
+        public override int Insert(T value)
         {
             int position = 0;
 
@@ -162,7 +74,7 @@ void InsertHelper(ref AVLTreeNode<T> node)
         /// <summary>Determines whether the <see cref="AVLTree{T}" /> contains a specific value. <code>Complexity: O(LogN)</code></summary>
         /// <param name="value">The element to locate in the <see cref="AVLTree{T}"/>.</param>
         /// <returns><c>true</c> if the <see cref="AVLTree{T}"/> contains <paramref name="value"/>; <c>false</c> otherwise.</returns>
-        public bool Find(T value)
+        public override bool Find(T value)
         {
             if (_root == null)
             {
@@ -188,7 +100,7 @@ public bool Find(T value)
         /// <summary>Removes one occurrence of a specific element from the <see cref="AVLTree{T}" />. <code>Complexity: O(LogN)</code></summary>
         /// <param name="value">The element to remove from the <see cref="AVLTree{T}"/>.</param>
         /// <returns><c>true</c> if the element was successfully removed from the <see cref="AVLTree{T}"/>; <c>false</c> otherwise.</returns>
-        public bool Remove(T value)
+        public override bool Remove(T value)
         {
             bool ret = true;
 
@@ -246,82 +158,5 @@ AVLTreeNode<T> RemoveHelper(AVLTreeNode<T> node)
             if (ret) Count--;
             return ret;
         }
-
-        /// <summary>Returns the list of the elements stored in the <see cref="AVLTree{T}" /> in-order. <code>Complexity: O(N)</code></summary>
-        /// <returns>List of in-order elements.</returns>
-        public T[] InOrderTraverse()
-        {
-            var output = new T[Count];
-            int i      = 0;
-
-            void IOTHelper(AVLTreeNode<T> node)
-            {
-                if (node == null)
-                {
-                    return;
-                }
-
-                IOTHelper(node.Left);
-                output[i++] = node.Value;
-                IOTHelper(node.Right);
-            }
-
-            IOTHelper(_root);
-
-            return output;
-        }
-
-        /// <summary>Returns the list of the elements stored in the <see cref="AVLTree{T}" /> pre-order. <code>Complexity: O(N)</code></summary>
-        /// <returns>List of pre-order elements.</returns>
-        public T[] PreOrderTraverse()
-        {
-            var output = new T[Count];
-            int i      = 0;
-
-            void POTHelper(AVLTreeNode<T> node)
-            {
-                if (node == null)
-                {
-                    return;
-                }
-
-                output[i++] = node.Value;
-                POTHelper(node.Left);
-                POTHelper(node.Right);
-            }
-
-            POTHelper(_root);
-
-            return output;
-        }
-
-        /// <summary>Returns the list of the elements stored in the <see cref="AVLTree{T}" /> post-order. <code>Complexity: O(N)</code></summary>
-        /// <returns>List of post-order elements.</returns>
-        public T[] PostOrderTraverse()
-        {
-            var output = new T[Count];
-            int i      = 0;
-
-            void POTHelper(AVLTreeNode<T> node)
-            {
-                if (node == null)
-                {
-                    return;
-                }
-
-                POTHelper(node.Left);
-                POTHelper(node.Right);
-                output[i++] = node.Value;
-            }
-
-            POTHelper(_root);
-
-            return output;
-        }
-
-        private int Compare(T x, T y)
-        {
-            return _comparer.Compare(x, y);
-        }
     }
 }

DStruct/BinaryTrees/AVLTreeNode.cs

@@ -2,12 +2,13 @@
 
 namespace DStruct.BinaryTrees
 {
-    class AVLTreeNode<T>
+    internal class AVLTreeNode<T> : IBinarySearchTreeNode<T>
     {
         public AVLTreeNode<T> Left;
         public AVLTreeNode<T> Right;
 
         public T Value { get; set; }
+
         public int LeftChildren { get; set; }
         public int Height { get; set; }
 
@@ -22,6 +23,9 @@ public int Balance
             }
         }
 
+        IBinarySearchTreeNode<T> IBinarySearchTreeNode<T>.Left => Left;
+        IBinarySearchTreeNode<T> IBinarySearchTreeNode<T>.Right => Right;
+
         public AVLTreeNode(T value, int height = 1, int leftChildren = 0)
         {
             Value        = value;

DStruct/BinaryTrees/BSTNode.cs

@@ -1,13 +1,16 @@
 namespace DStruct.BinaryTrees
 {
-    class BSTNode<T>
+    internal class BSTNode<T> : IBinarySearchTreeNode<T>
     {
         public BSTNode<T> Left;
         public BSTNode<T> Right;
 
         public T Value { get; set; }
         public int LeftChildren { get; set; }
 
+        IBinarySearchTreeNode<T> IBinarySearchTreeNode<T>.Left => Left;
+        IBinarySearchTreeNode<T> IBinarySearchTreeNode<T>.Right => Right;
+
         public BSTNode()
         {
         }