/// <summary>
/// Initializes a new instance of the <see cref="VanEmdeBoasTree"/> class
/// with the provided <paramref name="universe"/> size.
/// </summary>
/// <param name="universe">
/// The size of the universe for this tree.
/// </param>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="universe"/> is smaller than two.
/// -or-
/// <paramref name="universe"/> is not a power of two.
/// </exception>
/// <remarks>
/// Calling this constructor will create an empty van Emde Boas subtree recursively.
/// </remarks>
public VanEmdeBoasTree(int universe)
{
VanEmdeBoasTreeNode root;
try
{
root = new VanEmdeBoasTreeNode(universe);
}
catch (ArgumentOutOfRangeException ex)
{
throw new ArgumentOutOfRangeException(nameof(universe), universe, ex.Message);
}
Root = root;
}
/// <summary>
/// Initializes a new instance of the <see cref="VanEmdeBoasTreeNode"/> class
/// with the provided <paramref name="universe"/> size.
/// </summary>
/// <param name="universe">
/// The size of the universe for this node.
/// </param>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="universe"/> is smaller than two.
/// -or-
/// <paramref name="universe"/> is not a power of two.
/// </exception>
/// <remarks>
/// Calling this constructor will create an empty van Emde Boas subtree recursively.
/// </remarks>
public VanEmdeBoasTreeNode(int universe)
{
if (universe < 2)
{
throw new ArgumentOutOfRangeException(nameof(universe), universe, "The universe cannot be smaller than two.");
}
if (!Utility.IsPowerOfTwo(universe))
{
throw new ArgumentOutOfRangeException(nameof(universe), universe, "The universe must be a power of two.");
}
Universe = universe;
Maximum = null;
Minimum = null;
if (universe == 2)
{
// Base case: the node has no cluster or summary.
Cluster = null;
Summary = null;
}
else
{
int universeUpperSquareRoot = (int)Utility.UpperSquareRoot(universe);
int universeLowerSquareRoot = (int)Utility.LowerSquareRoot(universe);
Summary = new VanEmdeBoasTreeNode(universeUpperSquareRoot);
var clusterList = new List <VanEmdeBoasTreeNode>(universeUpperSquareRoot);
for (int i = 0; i < universeUpperSquareRoot; i++)
{
clusterList.Add(new VanEmdeBoasTreeNode(universeLowerSquareRoot));
}
Cluster = clusterList.AsReadOnly();
}
}