public void GetBalanceFactor_ForSeveralNodesInSampleTree_ExpectsCorrectValues()
{
/* The constructed tree is not AVL, however the method GetBalanceFactor should work regardless. */
var A = new AVLTreeNode <int, string>(50, "A");
var B = new AVLTreeNode <int, string>(20, "B");
var C = new AVLTreeNode <int, string>(10, "C");
var D = new AVLTreeNode <int, string>(40, "D");
var E = new AVLTreeNode <int, string>(30, "E");
A.Parent = null;
A.LeftChild = B;
A.RightChild = null;
B.Parent = A;
B.LeftChild = C;
B.RightChild = D;
C.Parent = B;
C.LeftChild = null;
C.RightChild = null;
D.Parent = B;
D.LeftChild = E;
D.RightChild = null;
E.Parent = D;
E.LeftChild = null;
E.RightChild = null;
Assert.AreEqual(-3, _tree.ComputeBalanceFactor(A));
Assert.AreEqual(1, _tree.ComputeBalanceFactor(B));
Assert.AreEqual(0, _tree.ComputeBalanceFactor(C));
Assert.AreEqual(-1, _tree.ComputeBalanceFactor(D));
Assert.AreEqual(0, _tree.ComputeBalanceFactor(E));
}
/// <summary>
/// Checks whether all the nodes in the AVL tree have expected balance factors between -1 and 1.
/// </summary>
/// <typeparam name="TKey">Type of the keys stored in the tree. </typeparam>
/// <typeparam name="TValue">Type of the values stored in the tree. </typeparam>
/// <param name="tree">An AVL tree</param>
/// <param name="nodes">List of all the nodes in the tree. </param>
/// <returns>True if the nodes all have expected balance factors, and false otherwise. </returns>
public bool HasExpectedBalanceFactor <TKey, TValue>(AVLTree <TKey, TValue> tree, List <AVLTreeNode <TKey, TValue> > nodes) where TKey : IComparable <TKey>, IEquatable <TKey>
{
foreach (AVLTreeNode <TKey, TValue> node in nodes)
{
int balanceFactor = tree.ComputeBalanceFactor(node);
Assert.IsTrue(balanceFactor >= -1 && balanceFactor <= 1);
}
return(true);
}