/// <summary>
/// Returns the number of nodes contained in the tree.
/// </summary>
/// <returns>The number of nodes contained in the tree.</returns>
public static int GetSize(this TreeEntityBase treeEntity)
{
if (treeEntity is null)
{
throw new ArgumentNullException(nameof(treeEntity));
}
return(TreeEntityExtensions.GetSubtreeSize(treeEntity.RootNode));
}
/// <summary>
/// Returns the number of nodes contained in the subtree of the given <paramref name="node"/>.
/// </summary>
private static int GetSubtreeSize(TreeNode?node)
{
if (node is null)
{
return(0);
}
int sum = 1; // Includes the node passed in.
for (int i = 0; i < node.ChildNodes.Count; i++)
{
sum += TreeEntityExtensions.GetSubtreeSize(node.ChildNodes[i]);
}
return(sum);
}