public void CopyToShouldWalkTheTreeForward()
{
int seed = 12345;
int RandomNext()
{
seed = (seed * 69069) + 12345;
return((seed >> 16) & 0x7FFF);
}
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>();
{
List <WeightedRedBlackTreeNode <int, int> > actualNodes = tree.ToList();
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
CollectionAssert.AreEqual(actualKeys, new int[0]);
}
List <int> keys = new List <int>();
for (int i = 0; i < 500; i++)
{
int key = RandomNext();
keys.Add(key);
tree.Add(key, i);
if (IsFibonacci(i))
{
List <WeightedRedBlackTreeNode <int, int> > actualNodes = tree.ToList();
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
int[] expectedKeys = keys.OrderBy(k => k).ToArray();
CollectionAssert.AreEqual(actualKeys, expectedKeys);
}
}
}
public void CanCopyToSpecialCaseTrees()
{
{
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>();
Assert.That(tree.Root, Is.Null);
// CopyTo should safely bail if the root is null.
WeightedRedBlackTreeNode <int, int>[] actualNodes = new WeightedRedBlackTreeNode <int, int> [0];
tree.CopyTo(actualNodes, 0);
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
CollectionAssert.AreEqual(actualKeys, new int[0]);
}
{
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>
{
{ 1, 10 },
};
// The above is a valid red-black tree with only one node.
Assert.That(tree.Root.Key, Is.EqualTo(1));
// CopyTo performs an inorder walk using Next(), starting at
// Root's minimum subnode.
List <WeightedRedBlackTreeNode <int, int> > actualNodes = tree.ToList();
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
CollectionAssert.AreEqual(actualKeys, new[] { 1 });
}
{
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>
{
{ 2, 20 },
{ 1, 10 },
};
// The above is a valid red-black tree in which the root is 2
// and it has a left child of 1. Let's check that to be sure...
Assert.That(tree.Root.Key, Is.EqualTo(2));
Assert.That(tree.Root.Left.Key, Is.EqualTo(1));
// CopyTo performs an inorder walk using Next(), starting at
// Root's minimum subnode. In this case, we ensure that
// Root is non-null and has a minimum subnode to start at.
List <WeightedRedBlackTreeNode <int, int> > actualNodes = tree.ToList();
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
CollectionAssert.AreEqual(actualKeys, new[] { 1, 2 });
}
{
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>
{
{ 1, 10 },
{ 2, 20 },
};
// The above is a valid red-black tree in which the root is 1
// and it has a right child of 2. Let's check that to be sure...
Assert.That(tree.Root.Key, Is.EqualTo(1));
Assert.That(tree.Root.Right.Key, Is.EqualTo(2));
// CopyTo performs an inorder walk using Next(), starting at
// Root's minimum subnode. In this case, we ensure that
// Root is non-null but has no minimum subnode to start at.
List <WeightedRedBlackTreeNode <int, int> > actualNodes = tree.ToList();
int[] actualKeys = actualNodes.Select(n => n.Key).ToArray();
CollectionAssert.AreEqual(actualKeys, new[] { 1, 2 });
}
}