private static ArneTreeNode <TKey, TValue> Add(ArneTreeNode <TKey, TValue> node, TValue leaf)
{
if (node == null)
{
return(new ArneTreeNode <TKey, TValue>(leaf, 1, null, null));
}
var compare = leaf.CompareTo(node.Value);
if (compare < 0)
{
node.Left = Add(node.Left, leaf);
}
else if (compare > 0)
{
node.Right = Add(node.Right, leaf);
}
else
{
return(null);
}
// Perform skew and then split.
// The conditionals that determine whether or not a rotation will occur or not are inside of the procedures, as given above.
node = node.Skew();
node = node.Split();
return(node);
}
public void NodeSkew()
{
// prepare data
var rootNode = new ArneTreeNode <Char, Char>('0', 0);
var tNode = new ArneTreeNode <Char, Char>('T', 1);
var lNode = new ArneTreeNode <Char, Char>('L', 1);
var aNode = new ArneTreeNode <Char, Char>('A', 2);
var bNode = new ArneTreeNode <Char, Char>('B', 2);
var rNode = new ArneTreeNode <Char, Char>('R', 2);
// initialize
rootNode.Right = tNode;
tNode.Left = lNode;
tNode.Right = rNode;
lNode.Left = aNode;
lNode.Right = bNode;
// perform operation
Assert.AreEqual(aNode, aNode.Skew());
Assert.AreEqual(lNode, lNode.Skew());
rootNode.Right = rootNode.Right.Skew();
// check results
// references
Assert.AreEqual(lNode, rootNode.Right);
Assert.AreEqual(aNode, lNode.Left);
Assert.AreEqual(tNode, lNode.Right);
Assert.AreEqual(bNode, tNode.Left);
Assert.AreEqual(rNode, tNode.Right);
// levels
Assert.AreEqual(0u, rootNode.Level);
Assert.AreEqual(1u, tNode.Level);
Assert.AreEqual(1u, lNode.Level);
Assert.AreEqual(2u, aNode.Level);
Assert.AreEqual(2u, bNode.Level);
Assert.AreEqual(2u, rNode.Level);
}