public static void TestHeight()
{
Func <int, double> HeightLimit = ((Func <Func <int, double> >)(() =>
{
// ln(sqrt(5) * (n + 2)) / ln((1 + sqrt(5)) / 2) - 2
var a = Math.Sqrt(5);
var b = 1.0 / Math.Log((1 + Math.Sqrt(5)) * 0.5);
return(c =>
{
return Math.Log(a * (c + 2)) * b - 2;
});
}))();
var d = new ImmutableSortedDictionary <int, Unit>();
var n = 10000;
var r = new Random();
for (int k = 0; k < n; k += 1)
{
d = d.AddOrSetItem(r.Next(0, n), default(Unit));
Debug.Assert(d.Height < HeightLimit(d.Count));
}
var Count = d.Count;
for (int k = 0; k < Count; k += 1)
{
d = d.Remove(d.TryGetPairByIndex(r.Next(0, d.Count)).Value.Key);
Debug.Assert(d.Height < HeightLimit(d.Count));
}
}