public void RotateLeftRotatesRootNode()
{
PointerBackedBinaryTree <int> testTree = new PointerBackedBinaryTree <int>();
testTree.Root = new PointerBackedBinaryTreeNode <int>(1, null);
testTree.Root.Right = new PointerBackedBinaryTreeNode <int>(2, testTree.Root);
testTree.RotateLeft(testTree.Root);
// Validate the entire tree structure after rotation, including internal pointers.
Assert.AreEqual(2, testTree.Root.Data);
Assert.IsNull(testTree.Root.Parent);
Assert.IsNull(testTree.Root.Right);
Assert.AreEqual(1, testTree.Root.Left.Data);
Assert.AreEqual(testTree.Root, testTree.Root.Left.Parent);
Assert.IsNull(testTree.Root.Left.Right);
Assert.IsNull(testTree.Root.Left.Left);
}
public void RotateLeftRotatesNode()
{
PointerBackedBinaryTree <int> testTree = new PointerBackedBinaryTree <int>();
testTree.Root = new PointerBackedBinaryTreeNode <int>(1, null);
testTree.Root.Right = new PointerBackedBinaryTreeNode <int>(2, testTree.Root);
testTree.Root.Right.Left = new PointerBackedBinaryTreeNode <int>(3, testTree.Root.Right);
testTree.Root.Right.Right = new PointerBackedBinaryTreeNode <int>(4, testTree.Root.Right);
testTree.Root.Right.Right.Left = new PointerBackedBinaryTreeNode <int>(5, testTree.Root.Right.Right);
testTree.Root.Right.Right.Right = new PointerBackedBinaryTreeNode <int>(6, testTree.Root.Right.Right);
testTree.RotateLeft(testTree.Root.Right);
// Validate the tree structure
Assert.AreEqual(1, testTree.Root.Data);
Assert.AreEqual(4, testTree.Root.Right.Data);
Assert.AreEqual(2, testTree.Root.Right.Left.Data);
Assert.AreEqual(6, testTree.Root.Right.Right.Data);
Assert.AreEqual(3, testTree.Root.Right.Left.Left.Data);
Assert.AreEqual(5, testTree.Root.Right.Left.Right.Data);
}