Added a ternary search tree.

SharpBag/Collections/TernarySearchTree.cs

@@ -0,0 +1,231 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.Contracts;
+using System.Linq;
+using System.Text;
+
+namespace SharpBag.Collections
+{
+	/// <summary>
+	/// A ternary search tree.
+	/// </summary>
+	/// <typeparam name="T">The type of items in the tree.</typeparam>
+	public class TernarySearchTree<T> : IEnumerable<T[]> where T : IComparable<T>
+	{
+		private class Node
+		{
+			public T Value { get; private set; }
+
+			public bool IsEnd { get; set; }
+
+			public Node Below { get; set; }
+
+			public Node Left { get; set; }
+
+			public Node Right { get; set; }
+
+			public Node(T value)
+			{
+				this.Value = value;
+				this.IsEnd = false;
+			}
+
+			public Node GetNextFor(T value)
+			{
+				return this.GetNextFor(this.Value.CompareTo(value));
+			}
+
+			public Node GetNextFor(int cmp)
+			{
+				if (cmp == 0) return this.Below;
+				if (cmp > 0) return this.Left;
+				return this.Right;
+			}
+
+			public void Add(Node node)
+			{
+				this.Add(node, this.Value.CompareTo(node.Value));
+			}
+
+			public void Add(Node node, int cmp)
+			{
+				if (cmp == 0) this.Below = node;
+				else if (cmp > 0) this.Left = node;
+				else this.Right = node;
+			}
+		}
+
+		/// <summary>
+		/// Gets the item count.
+		/// </summary>
+		public int Count { get; private set; }
+
+		/// <summary>
+		/// Gets the items.
+		/// </summary>
+		public IEnumerable<T[]> Items
+		{
+			get
+			{
+				foreach (var item in this.StartingWith(new T[0], this.Root))
+				{
+					yield return item;
+				}
+			}
+		}
+
+		private Node Root { get; set; }
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="TernarySearchTree&lt;T&gt;"/> class.
+		/// </summary>
+		public TernarySearchTree() { Count = 0; }
+
+		/// <summary>
+		/// Adds the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>Whether the sequence was new.</returns>
+		public virtual bool Add(T[] sequence)
+		{
+			Contract.Requires(sequence.Length > 0);
+			bool isNew = false;
+
+			if (this.Root == null)
+			{
+				this.Root = new Node(sequence[0]);
+				isNew = true;
+			}
+
+			Node cur = this.Root;
+			for (int i = 0; i < sequence.Length; i++)
+			{
+				int cmp = cur.Value.CompareTo(sequence[i]);
+
+				if (cmp == 0)
+				{
+					if (i < sequence.Length - 1)
+					{
+						if (cur.Below == null)
+						{
+							cur.Below = new Node(sequence[i + 1]);
+							isNew = true;
+						}
+
+						cur = cur.Below;
+					}
+				}
+				else if (cmp > 0)
+				{
+					if (cur.Left == null)
+					{
+						cur.Left = new Node(sequence[i]);
+						isNew = true;
+					}
+
+					cur = cur.Left;
+					i--;
+				}
+				else
+				{
+					if (cur.Right == null)
+					{
+						cur.Right = new Node(sequence[i]);
+						isNew = true;
+					}
+
+					cur = cur.Right;
+					i--;
+				}
+
+				if (i + 1 == sequence.Length)
+				{
+					if (!cur.IsEnd) isNew = true;
+					cur.IsEnd = true;
+				}
+			}
+
+			if (isNew) this.Count++;
+			return isNew;
+		}
+
+		/// <summary>
+		/// Determines whether the current instance contains the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>
+		///   <c>true</c> if the current instance contains the specified sequence; otherwise, <c>false</c>.
+		/// </returns>
+		public virtual bool Contains(T[] sequence)
+		{
+			Contract.Requires(sequence.Length > 0);
+			if (this.Root == null) return false;
+
+			Node cur = this.Root;
+			for (int i = 0; i < sequence.Length; i++)
+			{
+				int cmp = cur.Value.CompareTo(sequence[i]);
+				if (i == sequence.Length - 1 && cmp == 0) return cur.IsEnd;
+				cur = cur.GetNextFor(cmp);
+				if (cmp != 0) i--;
+				if (cur == null) return false;
+			}
+
+			return false;
+		}
+
+		/// <summary>
+		/// Gets all the sequences starting with the specified elements.
+		/// </summary>
+		/// <param name="sequence">The sequence of starting elements.</param>
+		/// <returns>The sequences starting with the specified elements.</returns>
+		public virtual IEnumerable<T[]> StartingWith(T[] sequence)
+		{
+			Contract.Requires(sequence.Length > 0);
+			if (this.Root == null) yield break;
+
+			Node cur = this.Root;
+			for (int i = 0; i < sequence.Length; i++)
+			{
+				int cmp = cur.Value.CompareTo(sequence[i]);
+				if (i == sequence.Length - 1 && cmp == 0) break;
+				cur = cur.GetNextFor(cmp);
+				if (cmp != 0) i--;
+				if (cur == null) yield break;
+			}
+
+			if (cur.IsEnd) yield return sequence;
+			if (cur.Below != null) foreach (T[] seq in this.StartingWith(sequence, cur.Below)) yield return seq;
+		}
+
+		private IEnumerable<T[]> StartingWith(T[] sequence, Node cur)
+		{
+			T[] seq = new T[sequence.Length + 1];
+			Array.Copy(sequence, seq, sequence.Length);
+			seq[sequence.Length] = cur.Value;
+
+			if (cur.IsEnd) yield return seq;
+			if (cur.Left != null) foreach (T[] s in this.StartingWith(sequence, cur.Left)) yield return s;
+			if (cur.Below != null) foreach (T[] s in this.StartingWith(seq, cur.Below)) yield return s;
+			if (cur.Right != null) foreach (T[] s in this.StartingWith(sequence, cur.Right)) yield return s;
+		}
+
+		/// <summary>
+		/// Gets the enumerator.
+		/// </summary>
+		/// <returns>The enumerator.</returns>
+		public IEnumerator<T[]> GetEnumerator()
+		{
+			foreach (var item in this.Items)
+			{
+				yield return item;
+			}
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return this.GetEnumerator();
+		}
+	}
+}

SharpBag/Collections/TernaryStringSearchTree.cs

@@ -0,0 +1,133 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace SharpBag.Collections
+{
+	/// <summary>
+	/// A ternary string-search tree.
+	/// </summary>
+	public class TernaryStringSearchTree : TernarySearchTree<char>, IEnumerable<string>
+	{
+		/// <summary>
+		/// Gets a value indicating whether the search tree is case sensitive.
+		/// </summary>
+		/// <value>
+		/// Whether the search tree is case sensitive.
+		/// </value>
+		public bool CaseSensitive { get; private set; }
+
+		/// <summary>
+		/// Gets the items.
+		/// </summary>
+		public new IEnumerable<string> Items
+		{
+			get
+			{
+				foreach (var item in base.Items)
+				{
+					yield return new String(item);
+				}
+			}
+		}
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="TernaryStringSearchTree"/> class.
+		/// </summary>
+		/// <param name="caseSensitive">Whether the search tree is case sensitive.</param>
+		public TernaryStringSearchTree(bool caseSensitive = true)
+		{
+			this.CaseSensitive = caseSensitive;
+		}
+
+		private char[] ToUpper(char[] sequence)
+		{
+			char[] upperSequence = new char[sequence.Length];
+			for (int i = 0; i < sequence.Length; i++) upperSequence[i] = Char.ToUpper(sequence[i]);
+			return upperSequence;
+		}
+
+		/// <summary>
+		/// Adds the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>Whether the sequence was new.</returns>
+		public bool Add(string sequence)
+		{
+			return base.Add(this.CaseSensitive ? sequence.ToCharArray() : this.ToUpper(sequence.ToCharArray()));
+		}
+
+		/// <summary>
+		/// Adds the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>Whether the sequence was new.</returns>
+		public override bool Add(char[] sequence)
+		{
+			return base.Add(this.CaseSensitive ? sequence : this.ToUpper(sequence));
+		}
+
+		/// <summary>
+		/// Determines whether the current instance contains the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>
+		///   <c>true</c> if the current instance contains the specified sequence; otherwise, <c>false</c>.
+		/// </returns>
+		public bool Contains(string sequence)
+		{
+			return base.Contains(this.CaseSensitive ? sequence.ToCharArray() : this.ToUpper(sequence.ToCharArray()));
+		}
+
+		/// <summary>
+		/// Determines whether the current instance contains the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence.</param>
+		/// <returns>
+		///   <c>true</c> if the current instance contains the specified sequence; otherwise, <c>false</c>.
+		/// </returns>
+		public override bool Contains(char[] sequence)
+		{
+			return base.Contains(this.CaseSensitive ? sequence : this.ToUpper(sequence));
+		}
+
+		/// <summary>
+		/// Gets all the sequences starting with the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence of starting elements.</param>
+		/// <returns>The sequences starting with the specified sequence.</returns>
+		public IEnumerable<string> StartingWith(string sequence)
+		{
+			return base.StartingWith(this.CaseSensitive ? sequence.ToCharArray() : this.ToUpper(sequence.ToCharArray())).Select(i => new String(i));
+		}
+
+		/// <summary>
+		/// Gets all the sequences starting with the specified sequence.
+		/// </summary>
+		/// <param name="sequence">The sequence of starting elements.</param>
+		/// <returns>The sequences starting with the specified sequence.</returns>
+		public new IEnumerable<string> StartingWith(char[] sequence)
+		{
+			return base.StartingWith(this.CaseSensitive ? sequence : this.ToUpper(sequence)).Select(i => new String(i));
+		}
+
+		/// <summary>
+		/// Gets the enumerator.
+		/// </summary>
+		/// <returns>The enumerator.</returns>
+		public new IEnumerator<string> GetEnumerator()
+		{
+			foreach (var item in this.Items)
+			{
+				yield return item;
+			}
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return this.GetEnumerator();
+		}
+	}
+}

SharpBag/SharpBag.csproj

@@ -75,6 +75,8 @@
     <Reference Include="WindowsBase" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Collections\TernarySearchTree.cs" />
+    <Compile Include="Collections\TernaryStringSearchTree.cs" />
     <Compile Include="DisposableAction.cs" />
     <Compile Include="CollectionExtensions.cs" />
     <Compile Include="Collections\BinaryHeap.cs" />
@@ -112,10 +114,10 @@
     <Compile Include="Math\ForFraction\ForBigInteger\Matrix.cs" />
     <Compile Include="Math\ForFraction\ForBigInteger\Vector.cs" />
     <Compile Include="Math\ForBigInteger\Fraction.cs" />
-    <Compile Include="Math\ForBigInteger\Polynomial.cs" />
-    <Compile Include="Math\ForComplex\Polynomial.cs" />
+    <Compile Include="Math\ForBigInteger\Polynomial.cs" />
+    <Compile Include="Math\ForComplex\Polynomial.cs" />
     <Compile Include="Math\ForFraction\ForInt32\Matrix.cs" />
-    <Compile Include="Math\ForFraction\ForInt32\Vector.cs" />
+    <Compile Include="Math\ForFraction\ForInt32\Vector.cs" />
     <Compile Include="Math\ForInt64\Polynomial.cs" />
     <Compile Include="Math\ForInt32\Polynomial.cs" />
     <Compile Include="Math\Geometry\Circle.cs" />