public void TreeShouldBeValidAfterManyRandomDeletions()
{
int seed = 12345;
int RandomNext()
{
seed = (seed * 69069) + 12345;
return((seed >> 16) & 0x7FFF);
}
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>();
List <Tuple <int, int> > insertions = new List <Tuple <int, int> >();
for (int i = 0; i < 500; i++)
{
int key = RandomNext();
insertions.Add(new Tuple <int, int>(key, i));
Assert.That(tree.Count, Is.EqualTo(i));
Assert.That(tree.TryGetValue(key, out int oldValue), Is.False);
Assert.That(tree.ContainsKey(key), Is.False);
tree.Add(key, i);
if (IsFibonacci(i))
{
tree.Validate();
}
Assert.That(tree.ContainsKey(key), Is.True);
Assert.That(tree[key], Is.EqualTo(i));
Assert.That(tree.TryGetValue(key, out int newValue), Is.True);
Assert.That(newValue, Is.EqualTo(i));
Assert.That(tree.Count, Is.EqualTo(i + 1));
}
for (int i = 0; i < 500; i++)
{
int key = insertions[i].Item1;
int value = insertions[i].Item2;
Assert.That(tree.ContainsKey(key), Is.True);
Assert.That(tree[key], Is.EqualTo(value));
Assert.That(tree.TryGetValue(key, out int newValue), Is.True);
Assert.That(newValue, Is.EqualTo(value));
Assert.That(tree.Count, Is.EqualTo(500 - i));
Assert.That(tree.Remove(key), Is.True);
if (IsFibonacci(i))
{
tree.Validate();
}
Assert.That(tree.ContainsKey(key), Is.False);
Assert.That(tree.TryGetValue(key, out int oldValue), Is.False);
Assert.That(tree.Count, Is.EqualTo(500 - i - 1));
}
}
public void NewTreeShouldBeEmpty()
{
WeightedRedBlackTree <int, int> tree = new WeightedRedBlackTree <int, int>();
Assert.That(tree.Root, Is.Null);
Assert.That(tree.Count, Is.Zero);
tree.Validate();
}