/mcs/class/Mono.C5/Test/trees/RedBlackTreeSetTests.cs

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/*
 Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
*/

using System;
using C5;
using NUnit.Framework;
using SCG = System.Collections.Generic;

namespace C5UnitTests.trees.TreeSet
{
  using CollectionOfInt = TreeSet<int>;

  [TestFixture]
  public class GenericTesters
  {
    [Test]
    public void TestEvents()
    {
      Fun<CollectionOfInt> factory = delegate() { return new CollectionOfInt(TenEqualityComparer.Default); };
      new C5UnitTests.Templates.Events.SortedIndexedTester<CollectionOfInt>().Test(factory);
    }

    [Test]
    public void Extensible()
    {
      C5UnitTests.Templates.Extensible.Clone.Tester<CollectionOfInt>();
      C5UnitTests.Templates.Extensible.Serialization.Tester<CollectionOfInt>();
    }
  }

  static class Factory
  {
    public static ICollection<T> New<T>() { return new TreeSet<T>(); }
  }


  [TestFixture]
  public class Formatting
  {
    ICollection<int> coll;
    IFormatProvider rad16;
    [SetUp]
    public void Init() { coll = Factory.New<int>(); rad16 = new RadixFormatProvider(16); }
    [TearDown]
    public void Dispose() { coll = null; rad16 = null; }
    [Test]
    public void Format()
    {
      Assert.AreEqual("{  }", coll.ToString());
      coll.AddAll<int>(new int[] { -4, 28, 129, 65530 });
      Assert.AreEqual("{ -4, 28, 129, 65530 }", coll.ToString());
      Assert.AreEqual("{ -4, 1C, 81, FFFA }", coll.ToString(null, rad16));
      Assert.AreEqual("{ -4, 28, 129... }", coll.ToString("L14", null));
      Assert.AreEqual("{ -4, 1C, 81... }", coll.ToString("L14", rad16));
    }
  }

  [TestFixture]
  public class Combined
	{
		private IIndexedSorted<KeyValuePair<int,int>> lst;


		[SetUp]
		public void Init()
		{
			lst = new TreeSet<KeyValuePair<int,int>>(new KeyValuePairComparer<int,int>(new IC()));
			for (int i = 0; i < 10; i++)
				lst.Add(new KeyValuePair<int,int>(i, i + 30));
		}


		[TearDown]
		public void Dispose() { lst = null; }


		[Test]
		public void Find()
		{
			KeyValuePair<int,int> p = new KeyValuePair<int,int>(3, 78);

			Assert.IsTrue(lst.Find(ref p));
			Assert.AreEqual(3, p.Key);
			Assert.AreEqual(33, p.Value);
			p = new KeyValuePair<int,int>(13, 78);
			Assert.IsFalse(lst.Find(ref p));
		}


		[Test]
		public void FindOrAdd()
		{
			KeyValuePair<int,int> p = new KeyValuePair<int,int>(3, 78);

			Assert.IsTrue(lst.FindOrAdd(ref p));
			Assert.AreEqual(3, p.Key);
			Assert.AreEqual(33, p.Value);
			p = new KeyValuePair<int,int>(13, 79);
			Assert.IsFalse(lst.FindOrAdd(ref p));
			Assert.AreEqual(13, lst[10].Key);
			Assert.AreEqual(79, lst[10].Value);
		}


		[Test]
		public void Update()
		{
			KeyValuePair<int,int> p = new KeyValuePair<int,int>(3, 78);

			Assert.IsTrue(lst.Update(p));
			Assert.AreEqual(3, lst[3].Key);
			Assert.AreEqual(78, lst[3].Value);
			p = new KeyValuePair<int,int>(13, 78);
			Assert.IsFalse(lst.Update(p));
		}


		[Test]
		public void UpdateOrAdd1()
		{
			KeyValuePair<int,int> p = new KeyValuePair<int,int>(3, 78);

			Assert.IsTrue(lst.UpdateOrAdd(p));
			Assert.AreEqual(3, lst[3].Key);
			Assert.AreEqual(78, lst[3].Value);
			p = new KeyValuePair<int,int>(13, 79);
			Assert.IsFalse(lst.UpdateOrAdd(p));
			Assert.AreEqual(13, lst[10].Key);
			Assert.AreEqual(79, lst[10].Value);
		}

        [Test]
        public void UpdateOrAdd2()
        {
            ICollection<String> coll = new TreeSet<String>();
            // s1 and s2 are distinct objects but contain the same text:
            String old, s1 = "abc", s2 = ("def" + s1).Substring(3);
            Assert.IsFalse(coll.UpdateOrAdd(s1, out old));
            Assert.AreEqual(null, old);
            Assert.IsTrue(coll.UpdateOrAdd(s2, out old));
            Assert.IsTrue(Object.ReferenceEquals(s1, old));
            Assert.IsFalse(Object.ReferenceEquals(s2, old));
        }

		[Test]
		public void RemoveWithReturn()
		{
			KeyValuePair<int,int> p = new KeyValuePair<int,int>(3, 78);

            Assert.IsTrue(lst.Remove(p, out p));
            Assert.AreEqual(3, p.Key);
			Assert.AreEqual(33, p.Value);
			Assert.AreEqual(4, lst[3].Key);
			Assert.AreEqual(34, lst[3].Value);
			p = new KeyValuePair<int,int>(13, 78);
            Assert.IsFalse(lst.Remove(p, out p));
        }
	}


	[TestFixture]
	public class Ranges
	{
		private TreeSet<int> tree;

		private SCG.IComparer<int> c;


		[SetUp]
		public void Init()
		{
			c = new IC();
			tree = new TreeSet<int>(c);
			for (int i = 1; i <= 10; i++)
			{
				tree.Add(i * 2);
			}
		}


		[Test]
		public void Enumerator()
		{
			SCG.IEnumerator<int> e = tree.RangeFromTo(5, 17).GetEnumerator();
			int i = 3;

			while (e.MoveNext())
			{
				Assert.AreEqual(2 * i++, e.Current);
			}

			Assert.AreEqual(9, i);
		}


		[Test]
		[ExpectedException(typeof(InvalidOperationException))]
		public void Enumerator2()
		{
			SCG.IEnumerator<int> e = tree.RangeFromTo(5, 17).GetEnumerator();
			int i = e.Current;
		}


		[Test]
		[ExpectedException(typeof(InvalidOperationException))]
		public void Enumerator3()
		{
			SCG.IEnumerator<int> e = tree.RangeFromTo(5, 17).GetEnumerator();

			while (e.MoveNext());

			int i = e.Current;
		}


		[Test]
		public void Remove()
		{
			int[] all = new int[] { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };

			tree.RemoveRangeFrom(18);
			Assert.IsTrue(IC.eq(tree, new int[] { 2, 4, 6, 8, 10, 12, 14, 16 }));
			tree.RemoveRangeFrom(28);
			Assert.IsTrue(IC.eq(tree, new int[] { 2, 4, 6, 8, 10, 12, 14, 16 }));
			tree.RemoveRangeFrom(2);
			Assert.IsTrue(IC.eq(tree));
			foreach (int i in all) tree.Add(i);

			tree.RemoveRangeTo(10);
			Assert.IsTrue(IC.eq(tree, new int[] { 10, 12, 14, 16, 18, 20 }));
			tree.RemoveRangeTo(2);
			Assert.IsTrue(IC.eq(tree, new int[] { 10, 12, 14, 16, 18, 20 }));
			tree.RemoveRangeTo(21);
			Assert.IsTrue(IC.eq(tree));
			foreach (int i in all) tree.Add(i);

			tree.RemoveRangeFromTo(4, 8);
			Assert.IsTrue(IC.eq(tree, 2, 8, 10, 12, 14, 16, 18, 20));
			tree.RemoveRangeFromTo(14, 28);
			Assert.IsTrue(IC.eq(tree, 2, 8, 10, 12));
			tree.RemoveRangeFromTo(0, 9);
			Assert.IsTrue(IC.eq(tree, 10, 12));
			tree.RemoveRangeFromTo(0, 81);
			Assert.IsTrue(IC.eq(tree));
		}

		[Test]
		public void Normal()
		{
			int[] all = new int[] { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };

			Assert.IsTrue(IC.eq(tree, all));
			Assert.IsTrue(IC.eq(tree.RangeAll(), all));
			Assert.AreEqual(10, tree.RangeAll().Count);
			Assert.IsTrue(IC.eq(tree.RangeFrom(11), new int[] { 12, 14, 16, 18, 20 }));
			Assert.AreEqual(5, tree.RangeFrom(11).Count);
			Assert.IsTrue(IC.eq(tree.RangeFrom(12), new int[] { 12, 14, 16, 18, 20 }));
			Assert.IsTrue(IC.eq(tree.RangeFrom(2), all));
			Assert.IsTrue(IC.eq(tree.RangeFrom(1), all));
			Assert.IsTrue(IC.eq(tree.RangeFrom(21), new int[] { }));
			Assert.IsTrue(IC.eq(tree.RangeFrom(20), new int[] { 20 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(8), new int[] { 2, 4, 6 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(7), new int[] { 2, 4, 6 }));
			Assert.AreEqual(3, tree.RangeTo(7).Count);
			Assert.IsTrue(IC.eq(tree.RangeTo(2), new int[] { }));
			Assert.IsTrue(IC.eq(tree.RangeTo(1), new int[] {  }));
			Assert.IsTrue(IC.eq(tree.RangeTo(3), new int[] { 2 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(20), new int[] { 2, 4, 6, 8, 10, 12, 14, 16, 18 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(21), all));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(7, 12), new int[] { 8, 10 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 11), new int[] { 6, 8, 10 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(1, 12), new int[] { 2, 4, 6, 8, 10 }));
			Assert.AreEqual(5, tree.RangeFromTo(1, 12).Count);
			Assert.IsTrue(IC.eq(tree.RangeFromTo(2, 12), new int[] { 2, 4, 6, 8, 10 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 21), new int[] { 6, 8, 10, 12, 14, 16, 18, 20 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 20), new int[] { 6, 8, 10, 12, 14, 16, 18 }));
		}


		[Test]
		public void Backwards()
		{
			int[] all = new int[] { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };
			int[] lla = new int[] { 20, 18, 16, 14, 12, 10, 8, 6, 4, 2 };

			Assert.IsTrue(IC.eq(tree, all));
			Assert.IsTrue(IC.eq(tree.RangeAll().Backwards(), lla));
			Assert.IsTrue(IC.eq(tree.RangeFrom(11).Backwards(), new int[] { 20, 18, 16, 14, 12 }));
            Assert.IsTrue(IC.eq(tree.RangeFrom(12).Backwards(), new int[] { 20, 18, 16, 14, 12 }));
			Assert.IsTrue(IC.eq(tree.RangeFrom(2).Backwards(), lla));
			Assert.IsTrue(IC.eq(tree.RangeFrom(1).Backwards(), lla));
			Assert.IsTrue(IC.eq(tree.RangeFrom(21).Backwards(), new int[] { }));
			Assert.IsTrue(IC.eq(tree.RangeFrom(20).Backwards(), new int[] { 20 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(8).Backwards(), new int[] { 6, 4, 2 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(7).Backwards(), new int[] { 6, 4, 2 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(2).Backwards(), new int[] { }));
			Assert.IsTrue(IC.eq(tree.RangeTo(1).Backwards(), new int[] {  }));
			Assert.IsTrue(IC.eq(tree.RangeTo(3).Backwards(), new int[] { 2 }));
			Assert.IsTrue(IC.eq(tree.RangeTo(20).Backwards(), new int[] { 18, 16, 14, 12, 10, 8, 6, 4, 2}));
			Assert.IsTrue(IC.eq(tree.RangeTo(21).Backwards(), lla));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(7, 12).Backwards(), new int[] { 10, 8 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 11).Backwards(), new int[] { 10, 8, 6 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(1, 12).Backwards(), new int[] { 10, 8, 6, 4, 2 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(2, 12).Backwards(), new int[] { 10, 8, 6, 4, 2 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 21).Backwards(), new int[] { 20, 18, 16, 14, 12, 10, 8, 6 }));
			Assert.IsTrue(IC.eq(tree.RangeFromTo(6, 20).Backwards(), new int[] { 18, 16, 14, 12, 10, 8, 6 }));
		}

		[Test]
		public void Direction()
		{
			Assert.AreEqual(EnumerationDirection.Forwards, tree.Direction);
			Assert.AreEqual(EnumerationDirection.Forwards, tree.RangeFrom(20).Direction);
			Assert.AreEqual(EnumerationDirection.Forwards, tree.RangeTo(7).Direction);
			Assert.AreEqual(EnumerationDirection.Forwards, tree.RangeFromTo(1, 12).Direction);
			Assert.AreEqual(EnumerationDirection.Forwards, tree.RangeAll().Direction);
			Assert.AreEqual(EnumerationDirection.Backwards, tree.Backwards().Direction);
			Assert.AreEqual(EnumerationDirection.Backwards, tree.RangeFrom(20).Backwards().Direction);
			Assert.AreEqual(EnumerationDirection.Backwards, tree.RangeTo(7).Backwards().Direction);
			Assert.AreEqual(EnumerationDirection.Backwards, tree.RangeFromTo(1, 12).Backwards().Direction);
			Assert.AreEqual(EnumerationDirection.Backwards, tree.RangeAll().Backwards().Direction);
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
			c = null;
		}
	}

	[TestFixture]
	public class BagItf
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
			for (int i = 10; i < 20; i++)
			{
				tree.Add(i);
				tree.Add(i + 10);
			}
		}


		[Test]
		public void Both()
		{
			Assert.AreEqual(0, tree.ContainsCount(7));
			Assert.AreEqual(1, tree.ContainsCount(10));
			tree.RemoveAllCopies(10);
			Assert.AreEqual(0, tree.ContainsCount(10));
			tree.RemoveAllCopies(7);
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}


	[TestFixture]
	public class Div
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
		}


		private void loadup()
		{
			for (int i = 10; i < 20; i++)
			{
				tree.Add(i);
				tree.Add(i + 10);
			}
		}

    [Test]
    [ExpectedException(typeof(NullReferenceException))]
    public void NullEqualityComparerinConstructor1()
    {
      new TreeSet<int>(null);
    }

    [Test]
    [ExpectedException(typeof(NullReferenceException))]
    public void NullEqualityComparerinConstructor3()
    {
      new TreeSet<int>(null, EqualityComparer<int>.Default);
    }

    [Test]
    [ExpectedException(typeof(NullReferenceException))]
    public void NullEqualityComparerinConstructor4()
    {
      new TreeSet<int>(Comparer<int>.Default, null);
    }

    [Test]
    [ExpectedException(typeof(NullReferenceException))]
    public void NullEqualityComparerinConstructor5()
    {
      new TreeSet<int>(null, null);
    }

    [Test]
    public void Choose()
    {
      tree.Add(7);
      Assert.AreEqual(7, tree.Choose());
    }

    [Test]
    [ExpectedException(typeof(NoSuchItemException))]
    public void BadChoose()
    {
      tree.Choose();
    }


    [Test]
		public void NoDuplicates()
		{
			Assert.IsFalse(tree.AllowsDuplicates);
			loadup();
			Assert.IsFalse(tree.AllowsDuplicates);
		}

		[Test]
		public void Add()
		{
			Assert.IsTrue(tree.Add(17));
			Assert.IsFalse(tree.Add(17));
			Assert.IsTrue(tree.Add(18));
			Assert.IsFalse(tree.Add(18));
			Assert.AreEqual(2, tree.Count);
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}


	[TestFixture]
	public class FindOrAdd
	{
		private TreeSet<KeyValuePair<int,string>> bag;


		[SetUp]
		public void Init()
		{
			bag = new TreeSet<KeyValuePair<int,string>>(new KeyValuePairComparer<int,string>(new IC()));
		}


		[TearDown]
		public void Dispose()
		{
			bag = null;
		}


		[Test]
		public void Test()
		{
			KeyValuePair<int,string> p = new KeyValuePair<int,string>(3, "tre");

			Assert.IsFalse(bag.FindOrAdd(ref p));
			p.Value = "drei";
			Assert.IsTrue(bag.FindOrAdd(ref p));
			Assert.AreEqual("tre", p.Value);
			p.Value = "three";
			Assert.AreEqual(1, bag.ContainsCount(p));
			Assert.AreEqual("tre", bag[0].Value);
		}
	}

  [TestFixture]
  public class FindPredicate
  {
    private TreeSet<int> list;
    Fun<int, bool> pred;

    [SetUp]
    public void Init()
    {
      list = new TreeSet<int>(TenEqualityComparer.Default);
      pred = delegate(int i) { return i % 5 == 0; };
    }

    [TearDown]
    public void Dispose() { list = null; }

    [Test]
    public void Find()
    {
      int i;
      Assert.IsFalse(list.Find(pred, out i));
      list.AddAll<int>(new int[] { 4, 22, 67, 37 });
      Assert.IsFalse(list.Find(pred, out i));
      list.AddAll<int>(new int[] { 45, 122, 675, 137 });
      Assert.IsTrue(list.Find(pred, out i));
      Assert.AreEqual(45, i);
    }

    [Test]
    public void FindLast()
    {
      int i;
      Assert.IsFalse(list.FindLast(pred, out i));
      list.AddAll<int>(new int[] { 4, 22, 67, 37 });
      Assert.IsFalse(list.FindLast(pred, out i));
      list.AddAll<int>(new int[] { 45, 122, 675, 137 });
      Assert.IsTrue(list.FindLast(pred, out i));
      Assert.AreEqual(675, i);
    }

    [Test]
    public void FindIndex()
    {
      Assert.IsFalse(0 <= list.FindIndex(pred));
      list.AddAll<int>(new int[] { 4, 22, 67, 37 });
      Assert.IsFalse(0 <= list.FindIndex(pred));
      list.AddAll<int>(new int[] { 45, 122, 675, 137 });
      Assert.AreEqual(3, list.FindIndex(pred));
    }

    [Test]
    public void FindLastIndex()
    {
      Assert.IsFalse(0 <= list.FindLastIndex(pred));
      list.AddAll<int>(new int[] { 4, 22, 67, 37 });
      Assert.IsFalse(0 <= list.FindLastIndex(pred));
      list.AddAll<int>(new int[] { 45, 122, 675, 137 });
      Assert.AreEqual(7, list.FindLastIndex(pred));
    }
  }

  [TestFixture]
  public class UniqueItems
  {
    private TreeSet<int> list;

    [SetUp]
    public void Init() { list = new TreeSet<int>(); }

    [TearDown]
    public void Dispose() { list = null; }

    [Test]
    public void Test()
    {
      Assert.IsTrue(IC.seteq(list.UniqueItems()));
      Assert.IsTrue(IC.seteq(list.ItemMultiplicities()));
      list.AddAll<int>(new int[] { 7, 9, 7 });
      Assert.IsTrue(IC.seteq(list.UniqueItems(), 7, 9));
      Assert.IsTrue(IC.seteq(list.ItemMultiplicities(), 7, 1, 9, 1));
    }
  }

  [TestFixture]
  public class ArrayTest
	{
		private TreeSet<int> tree;

		int[] a;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
			a = new int[10];
			for (int i = 0; i < 10; i++)
				a[i] = 1000 + i;
		}


		[TearDown]
		public void Dispose() { tree = null; }


		private string aeq(int[] a, params int[] b)
		{
			if (a.Length != b.Length)
				return "Lengths differ: " + a.Length + " != " + b.Length;

			for (int i = 0; i < a.Length; i++)
				if (a[i] != b[i])
					return String.Format("{0}'th elements differ: {1} != {2}", i, a[i], b[i]);

			return "Alles klar";
		}


		[Test]
		public void ToArray()
		{
			Assert.AreEqual("Alles klar", aeq(tree.ToArray()));
			tree.Add(7);
			tree.Add(4);
			Assert.AreEqual("Alles klar", aeq(tree.ToArray(), 4, 7));
		}


		[Test]
		public void CopyTo()
		{
			tree.CopyTo(a, 1);
			Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009));
			tree.Add(6);
			tree.CopyTo(a, 2);
			Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 1004, 1005, 1006, 1007, 1008, 1009));
			tree.Add(4);
			tree.Add(9);
			tree.CopyTo(a, 4);
			Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 4, 6, 9, 1007, 1008, 1009));
			tree.Clear();
			tree.Add(7);
			tree.CopyTo(a, 9);
			Assert.AreEqual("Alles klar", aeq(a, 1000, 1001, 6, 1003, 4, 6, 9, 1007, 1008, 7));
		}


		[Test]
    [ExpectedException(typeof(ArgumentOutOfRangeException))]
    public void CopyToBad()
		{
			tree.CopyTo(a, 11);
		}


		[Test]
		[ExpectedException(typeof(ArgumentOutOfRangeException))]
		public void CopyToBad2()
		{
			tree.CopyTo(a, -1);
		}


		[Test]
    [ExpectedException(typeof(ArgumentOutOfRangeException))]
    public void CopyToTooFar()
		{
			tree.Add(3);
			tree.Add(4);
			tree.CopyTo(a, 9);
		}
	}




	[TestFixture]
	public class Remove
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
			for (int i = 10; i < 20; i++)
			{
				tree.Add(i);
				tree.Add(i + 10);
			}
		}


		[Test]
		public void SmallTrees()
		{
			tree.Clear();
			tree.Add(7);
			tree.Add(9);
			Assert.IsTrue(tree.Remove(7));
			Assert.IsTrue(tree.Check(""));
		}


		[Test]
		public void ByIndex()
		{
			//Remove root!
			int n = tree.Count;
			int i = tree[10];

			tree.RemoveAt(10);
			Assert.IsTrue(tree.Check(""));
			Assert.IsFalse(tree.Contains(i));
			Assert.AreEqual(n - 1, tree.Count);

			//Low end
			i = tree.FindMin();
			tree.RemoveAt(0);
			Assert.IsTrue(tree.Check(""));
			Assert.IsFalse(tree.Contains(i));
			Assert.AreEqual(n - 2, tree.Count);

			//high end
			i = tree.FindMax();
			tree.RemoveAt(tree.Count - 1);
			Assert.IsTrue(tree.Check(""));
			Assert.IsFalse(tree.Contains(i));
			Assert.AreEqual(n - 3, tree.Count);

			//Some leaf
			i = 18;
			tree.RemoveAt(7);
			Assert.IsTrue(tree.Check(""));
			Assert.IsFalse(tree.Contains(i));
			Assert.AreEqual(n - 4, tree.Count);
		}


		[Test]
		public void AlmostEmpty()
		{
			//Almost empty
			tree.Clear();
			tree.Add(3);
			tree.RemoveAt(0);
			Assert.IsTrue(tree.Check(""));
			Assert.IsFalse(tree.Contains(3));
			Assert.AreEqual(0, tree.Count);
		}


		[Test]
		[ExpectedException(typeof(IndexOutOfRangeException), ExpectedMessage="Index out of range for sequenced collectionvalue")]
		public void Empty()
		{
			tree.Clear();
			tree.RemoveAt(0);
		}


		[Test]
		[ExpectedException(typeof(IndexOutOfRangeException), ExpectedMessage="Index out of range for sequenced collectionvalue")]
		public void HighIndex()
		{
			tree.RemoveAt(tree.Count);
		}


		[Test]
		[ExpectedException(typeof(IndexOutOfRangeException), ExpectedMessage="Index out of range for sequenced collectionvalue")]
		public void LowIndex()
		{
			tree.RemoveAt(-1);
		}


		[Test]
		public void Normal()
		{
			Assert.IsFalse(tree.Remove(-20));

			//No demote case, with move_item
			Assert.IsTrue(tree.Remove(20));
			Assert.IsTrue(tree.Check("T1"));
			Assert.IsFalse(tree.Remove(20));

			//plain case 2
			Assert.IsTrue(tree.Remove(14));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");

			//case 1b
			Assert.IsTrue(tree.Remove(25));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");

			//case 1c
			Assert.IsTrue(tree.Remove(29));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");

			//1a (terminating)
			Assert.IsTrue(tree.Remove(10));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");

			//2+1b
			Assert.IsTrue(tree.Remove(12));
			Assert.IsTrue(tree.Remove(11));

			//1a+1b
			Assert.IsTrue(tree.Remove(18));
			Assert.IsTrue(tree.Remove(13));
			Assert.IsTrue(tree.Remove(15));

			//2+1c
			for (int i = 0; i < 10; i++)
				tree.Add(50 - 2 * i);

			Assert.IsTrue(tree.Remove(42));
			Assert.IsTrue(tree.Remove(38));
			Assert.IsTrue(tree.Remove(28));
			Assert.IsTrue(tree.Remove(40));

			//
			Assert.IsTrue(tree.Remove(16));
			Assert.IsTrue(tree.Remove(23));
			Assert.IsTrue(tree.Remove(17));
			Assert.IsTrue(tree.Remove(19));
			Assert.IsTrue(tree.Remove(50));
			Assert.IsTrue(tree.Remove(26));
			Assert.IsTrue(tree.Remove(21));
			Assert.IsTrue(tree.Remove(22));
			Assert.IsTrue(tree.Remove(24));
			for (int i = 0; i < 48; i++)
				tree.Remove(i);

			//Almost empty tree:
			Assert.IsFalse(tree.Remove(26));
			Assert.IsTrue(tree.Remove(48));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");

			//Empty tree:
			Assert.IsFalse(tree.Remove(26));
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}



	[TestFixture]
	public class PredecessorStructure
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
		}


		private void loadup()
		{
			for (int i = 0; i < 20; i++)
				tree.Add(2 * i);
		}

        [Test]
        public void FindPredecessor()
        {
            loadup();
            int res;
            Assert.IsTrue(tree.TryPredecessor(7, out res) && res == 6);
            Assert.IsTrue(tree.TryPredecessor(8, out res) && res == 6);

            //The bottom
            Assert.IsTrue(tree.TryPredecessor(1, out res) && res == 0);

            //The top
            Assert.IsTrue(tree.TryPredecessor(39, out res) && res == 38);
        }

        [Test]
        public void FindPredecessorTooLow1()
        {
            int res;
            Assert.IsFalse(tree.TryPredecessor(-2, out res));
            Assert.AreEqual(0, res);
            Assert.IsFalse(tree.TryPredecessor(0, out res));
            Assert.AreEqual(0, res);
        }

        [Test]
        public void FindWeakPredecessor()
        {
            loadup();
            int res;
            Assert.IsTrue(tree.TryWeakPredecessor(7, out res) && res == 6);
            Assert.IsTrue(tree.TryWeakPredecessor(8, out res) && res == 8);

            //The bottom
            Assert.IsTrue(tree.TryWeakPredecessor(1, out res) && res == 0);
            Assert.IsTrue(tree.TryWeakPredecessor(0, out res) && res == 0);

            //The top
            Assert.IsTrue(tree.TryWeakPredecessor(39, out res) && res == 38);
            Assert.IsTrue(tree.TryWeakPredecessor(38, out res) && res == 38);
        }

        [Test]
        public void FindWeakPredecessorTooLow1()
        {
            int res;
            Assert.IsFalse(tree.TryWeakPredecessor(-1, out res));
            Assert.AreEqual(0, res);
        }

        [Test]
        public void FindSuccessor()
        {
            loadup();
            int res;
            Assert.IsTrue(tree.TrySuccessor(7, out res) && res == 8);
            Assert.IsTrue(tree.TrySuccessor(8, out res) && res == 10);

            //The bottom
            Assert.IsTrue(tree.TrySuccessor(0, out res) && res == 2);
            Assert.IsTrue(tree.TrySuccessor(-1, out res) && res == 0);

            //The top
            Assert.IsTrue(tree.TrySuccessor(37, out res) && res == 38);
        }

        [Test]
        public void FindSuccessorTooHigh()
        {
            int res;
            Assert.IsFalse(tree.TrySuccessor(38, out res));
            Assert.AreEqual(0, res);
            Assert.IsFalse(tree.TrySuccessor(39, out res));
            Assert.AreEqual(0, res);
        }

        [Test]
        public void FindWeakSuccessor()
        {
            loadup();
            int res;
            Assert.IsTrue(tree.TryWeakSuccessor(6, out res) && res == 6);
            Assert.IsTrue(tree.TryWeakSuccessor(7, out res) && res == 8);

            //The bottom
            Assert.IsTrue(tree.TryWeakSuccessor(-1, out res) && res == 0);
            Assert.IsTrue(tree.TryWeakSuccessor(0, out res) && res == 0);

            //The top
            Assert.IsTrue(tree.TryWeakSuccessor(37, out res) && res == 38);
            Assert.IsTrue(tree.TryWeakSuccessor(38, out res) && res == 38);
        }

        [Test]
        public void FindWeakSuccessorTooHigh1()
        {
            int res;
            Assert.IsFalse(tree.TryWeakSuccessor(39, out res));
            Assert.AreEqual(0, res);
        }


		[Test]
		public void Predecessor()
		{
			loadup();
			Assert.AreEqual(6, tree.Predecessor(7));
			Assert.AreEqual(6, tree.Predecessor(8));

			//The bottom
			Assert.AreEqual(0, tree.Predecessor(1));

			//The top
			Assert.AreEqual(38, tree.Predecessor(39));
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void PredecessorTooLow1()
		{
			tree.Predecessor(-2);
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void PredecessorTooLow2()
		{
			tree.Predecessor(0);
		}


		[Test]
		public void WeakPredecessor()
		{
			loadup();
			Assert.AreEqual(6, tree.WeakPredecessor(7));
			Assert.AreEqual(8, tree.WeakPredecessor(8));

			//The bottom
			Assert.AreEqual(0, tree.WeakPredecessor(1));
			Assert.AreEqual(0, tree.WeakPredecessor(0));

			//The top
			Assert.AreEqual(38, tree.WeakPredecessor(39));
			Assert.AreEqual(38, tree.WeakPredecessor(38));
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void WeakPredecessorTooLow1()
		{
			tree.WeakPredecessor(-2);
		}


		[Test]
		public void Successor()
		{
			loadup();
			Assert.AreEqual(8, tree.Successor(7));
			Assert.AreEqual(10, tree.Successor(8));

			//The bottom
			Assert.AreEqual(2, tree.Successor(0));
			Assert.AreEqual(0, tree.Successor(-1));

			//The top
			Assert.AreEqual(38, tree.Successor(37));
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void SuccessorTooHigh1()
		{
			tree.Successor(38);
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void SuccessorTooHigh2()
		{
			tree.Successor(39);
		}


		[Test]
		public void WeakSuccessor()
		{
			loadup();
			Assert.AreEqual(6, tree.WeakSuccessor(6));
			Assert.AreEqual(8, tree.WeakSuccessor(7));

			//The bottom
			Assert.AreEqual(0, tree.WeakSuccessor(-1));
			Assert.AreEqual(0, tree.WeakSuccessor(0));

			//The top
			Assert.AreEqual(38, tree.WeakSuccessor(37));
			Assert.AreEqual(38, tree.WeakSuccessor(38));
		}


		[Test]
        [ExpectedException(typeof(NoSuchItemException))]
        public void WeakSuccessorTooHigh1()
		{
			tree.WeakSuccessor(39);
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}



	[TestFixture]
	public class PriorityQueue
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
		}


		private void loadup()
		{
			foreach (int i in new int[] { 1, 2, 3, 4 })
				tree.Add(i);
		}


		[Test]
		public void Normal()
		{
			loadup();
			Assert.AreEqual(1, tree.FindMin());
			Assert.AreEqual(4, tree.FindMax());
			Assert.AreEqual(1, tree.DeleteMin());
			Assert.AreEqual(4, tree.DeleteMax());
			Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
			Assert.AreEqual(2, tree.FindMin());
			Assert.AreEqual(3, tree.FindMax());
			Assert.AreEqual(2, tree.DeleteMin());
			Assert.AreEqual(3, tree.DeleteMax());
			Assert.IsTrue(tree.Check("Normal test 2"), "Bad tree");
		}


		[Test]
		[ExpectedException(typeof(NoSuchItemException))]
		public void Empty1()
		{
			tree.FindMin();
		}


		[Test]
		[ExpectedException(typeof(NoSuchItemException))]
		public void Empty2()
		{
			tree.FindMax();
		}


		[Test]
		[ExpectedException(typeof(NoSuchItemException))]
		public void Empty3()
		{
			tree.DeleteMin();
		}


		[Test]
		[ExpectedException(typeof(NoSuchItemException))]
		public void Empty4()
		{
			tree.DeleteMax();
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}



	[TestFixture]
	public class IndexingAndCounting
	{
		private TreeSet<int> tree;


		[SetUp]
		public void Init()
		{
			tree = new TreeSet<int>(new IC());
		}


		private void populate()
		{
			tree.Add(30);
			tree.Add(50);
			tree.Add(10);
			tree.Add(70);
		}


		[Test]
		public void ToArray()
		{
			populate();

			int[] a = tree.ToArray();

			Assert.AreEqual(4, a.Length);
			Assert.AreEqual(10, a[0]);
			Assert.AreEqual(30, a[1]);
			Assert.AreEqual(50, a[2]);
			Assert.AreEqual(70, a[3]);
		}


		[Test]
		public void GoodIndex()
		{
			Assert.AreEqual(-1, tree.IndexOf(20));
			Assert.AreEqual(-1, tree.LastIndexOf(20));
			populate();
			Assert.AreEqual(10, tree[0]);
			Assert.AreEqual(30, tree[1]);
			Assert.AreEqual(50, tree[2]);
			Assert.AreEqual(70, tree[3]);
			Assert.AreEqual(0, tree.IndexOf(10));
			Assert.AreEqual(1, tree.IndexOf(30));
			Assert.AreEqual(2, tree.IndexOf(50));
			Assert.AreEqual(3, tree.IndexOf(70));
			Assert.AreEqual(~1, tree.IndexOf(20));
			Assert.AreEqual(~0, tree.IndexOf(0));
			Assert.AreEqual(~4, tree.IndexOf(90));
			Assert.AreEqual(0, tree.LastIndexOf(10));
			Assert.AreEqual(1, tree.LastIndexOf(30));
			Assert.AreEqual(2, tree.LastIndexOf(50));
			Assert.AreEqual(3, tree.LastIndexOf(70));
			Assert.AreEqual(~1, tree.LastIndexOf(20));
			Assert.AreEqual(~0, tree.LastIndexOf(0));
			Assert.AreEqual(~4, tree.LastIndexOf(90));
		}


		[Test]
		[ExpectedException(typeof(IndexOutOfRangeException))]
		public void IndexTooLarge()
		{
			populate();
			Console.WriteLine(tree[4]);
		}


		[Test]
		[ExpectedException(typeof(IndexOutOfRangeException))]
		public void IndexTooSmall()
		{
			populate();
			Console.WriteLine(tree[-1]);
		}


		[Test]
		public void FilledTreeOutsideInput()
		{
			populate();
			Assert.AreEqual(0, tree.CountFrom(90));
			Assert.AreEqual(0, tree.CountFromTo(-20, 0));
			Assert.AreEqual(0, tree.CountFromTo(80, 100));
			Assert.AreEqual(0, tree.CountTo(0));
			Assert.AreEqual(4, tree.CountTo(90));
			Assert.AreEqual(4, tree.CountFromTo(-20, 90));
			Assert.AreEqual(4, tree.CountFrom(0));
		}


		[Test]
		public void FilledTreeIntermediateInput()
		{
			populate();
			Assert.AreEqual(3, tree.CountFrom(20));
			Assert.AreEqual(1, tree.CountFromTo(20, 40));
			Assert.AreEqual(2, tree.CountTo(40));
		}


		[Test]
		public void FilledTreeMatchingInput()
		{
			populate();
			Assert.AreEqual(3, tree.CountFrom(30));
			Assert.AreEqual(2, tree.CountFromTo(30, 70));
			Assert.AreEqual(0, tree.CountFromTo(50, 30));
			Assert.AreEqual(0, tree.CountFromTo(50, 50));
			Assert.AreEqual(0, tree.CountTo(10));
			Assert.AreEqual(2, tree.CountTo(50));
		}


		[Test]
		public void CountEmptyTree()
		{
			Assert.AreEqual(0, tree.CountFrom(20));
			Assert.AreEqual(0, tree.CountFromTo(20, 40));
			Assert.AreEqual(0, tree.CountTo(40));
		}


		[TearDown]
		public void Dispose()
		{
			tree = null;
		}
	}




	namespace ModificationCheck
	{
		[TestFixture]
		public class Enumerator
		{
			private TreeSet<int> tree;

			private SCG.IEnumerator<int> e;


			[SetUp]
			public void Init()
			{
				tree = new TreeSet<int>(new IC());
				for (int i = 0; i < 10; i++)
					tree.Add(i);

				e = tree.GetEnumerator();
			}


			[Test]
			public void CurrentAfterModification()
			{
				e.MoveNext();
				tree.Add(34);
				Assert.AreEqual(0, e.Current);
			}


			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterAdd()
			{
				tree.Add(34);
				e.MoveNext();
			}




			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterRemove()
			{
				tree.Remove(34);
				e.MoveNext();
			}


			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterClear()
			{
				tree.Clear();
				e.MoveNext();
			}


			[TearDown]
			public void Dispose()
			{
				tree = null;
				e = null;
			}
		}



		[TestFixture]
		public class RangeEnumerator
		{
			private TreeSet<int> tree;

			private SCG.IEnumerator<int> e;


			[SetUp]
			public void Init()
			{
				tree = new TreeSet<int>(new IC());
				for (int i = 0; i < 10; i++)
					tree.Add(i);

				e = tree.RangeFromTo(3, 7).GetEnumerator();
			}


			[Test]
			public void CurrentAfterModification()
			{
				e.MoveNext();
				tree.Add(34);
				Assert.AreEqual(3, e.Current);
			}


			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterAdd()
			{
				tree.Add(34);
				e.MoveNext();
			}




			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterRemove()
			{
				tree.Remove(34);
				e.MoveNext();
			}


			[Test]
      [ExpectedException(typeof(CollectionModifiedException))]
      public void MoveNextAfterClear()
			{
				tree.Clear();
				e.MoveNext();
			}


			[TearDown]
			public void Dispose()
			{
				tree = null;
				e = null;
			}
		}
	}




	namespace PathcopyPersistence
	{
		[TestFixture]
		public class Navigation
		{
			private TreeSet<int> tree, snap;

			private SCG.IComparer<int> ic;


			[SetUp]
			public void Init()
			{
				ic = new IC();
				tree = new TreeSet<int>(ic);
				for (int i = 0; i <= 20; i++)
					tree.Add(2 * i + 1);

				snap = (TreeSet<int>)tree.Snapshot();
				for (int i = 0; i <= 10; i++)
					tree.Remove(4 * i + 1);
			}


			private bool twomodeleven(int i)
			{
				return i % 11 == 2;
			}


			[Test]
			public void InternalEnum()
			{
				Assert.IsTrue(IC.eq(snap.FindAll(new Fun<int, bool>(twomodeleven)), 13, 35));
			}

			
			public void MoreCut() { }

			[Test]
			public void Cut()
			{
				int lo, hi;
				bool lv, hv;

				Assert.IsFalse(snap.Cut(new HigherOrder.CubeRoot(64), out lo, out lv, out hi, out hv));
				Assert.IsTrue(lv && hv);
				Assert.AreEqual(5, hi);
				Assert.AreEqual(3, lo);
				Assert.IsTrue(snap.Cut(new HigherOrder.CubeRoot(125), out lo, out lv, out hi, out hv));
				Assert.IsTrue(lv && hv);
				Assert.AreEqual(7, hi);
				Assert.AreEqual(3, lo);
				Assert.IsFalse(snap.Cut(new HigherOrder.CubeRoot(125000), out lo, out lv, out hi, out hv));
				Assert.IsTrue(lv && !hv);
				Assert.AreEqual(41, lo);
				Assert.IsFalse(snap.Cut(new HigherOrder.CubeRoot(-27), out lo, out lv, out hi, out hv));
				Assert.IsTrue(!lv && hv);
				Assert.AreEqual(1, hi);
			}


			[Test]
			public void Range()
			{
				Assert.IsTrue(IC.eq(snap.RangeFromTo(5, 16), 5, 7, 9, 11, 13, 15));
				Assert.IsTrue(IC.eq(snap.RangeFromTo(5, 17), 5, 7, 9, 11, 13, 15));
				Assert.IsTrue(IC.eq(snap.RangeFromTo(6, 16), 7, 9, 11, 13, 15));
				//Assert.AreEqual(snap.RangeFromTo(6, 16).Count, 5);
			}


			[Test]
			public void Contains()
			{
				Assert.IsTrue(snap.Contains(5));
			}


			[Test]
			public void FindMin()
			{
				Assert.AreEqual(1, snap.FindMin());
			}


			[Test]
			public void FindMax()
			{
				Assert.AreEqual(41, snap.FindMax());
			}

            [Test]
            public void FindPredecessor()
            {
                int res;
                Assert.IsTrue(snap.TryPredecessor(15, out res) && res == 13);
                Assert.IsTrue(snap.TryPredecessor(16, out res) && res == 15);
                Assert.IsTrue(snap.TryPredecessor(17, out res) && res == 15);
                Assert.IsTrue(snap.TryPredecessor(18, out res) && res == 17);

                Assert.IsTrue(snap.TryPredecessor(2, out res) && res == 1);

                Assert.IsFalse(snap.TryPredecessor(1, out res));
                Assert.AreEqual(0, res);
            }


            [Test]
            public void FindSuccessor()
            {
                int res;
                Assert.IsTrue(snap.TrySuccessor(15, out res) && res == 17);
                Assert.IsTrue(snap.TrySuccessor(16, out res) && res == 17);
                Assert.IsTrue(snap.TrySuccessor(17, out res) && res == 19);
                Assert.IsTrue(snap.TrySuccessor(18, out res) && res == 19);

                Assert.IsTrue(snap.TrySuccessor(40, out res) && res == 41);
                
                Assert.IsFalse(snap.TrySuccessor(41, out res));
                Assert.AreEqual(0, res);
            }


            [Test]
            public void FindWeakPredecessor()
            {
                int res;
                Assert.IsTrue(snap.TryWeakPredecessor(15, out res) && res == 15);
                Assert.IsTrue(snap.TryWeakPredecessor(16, out res) && res == 15);
                Assert.IsTrue(snap.TryWeakPredecessor(17, out res) && res == 17);
                Assert.IsTrue(snap.TryWeakPredecessor(18, out res) && res == 17);

                Assert.IsTrue(snap.TryWeakPredecessor(1, out res) && res == 1);

                Assert.IsFalse(snap.TryWeakPredecessor(0, out res));
                Assert.AreEqual(0, res);
            }


            [Test]
            public void FindWeakSuccessor()
            {
                int res;
                Assert.IsTrue(snap.TryWeakSuccessor(15, out res) && res == 15);
                Assert.IsTrue(snap.TryWeakSuccessor(16, out res) && res == 17);
                Assert.IsTrue(snap.TryWeakSuccessor(17, out res) && res == 17);
                Assert.IsTrue(snap.TryWeakSuccessor(18, out res) && res == 19);

                Assert.IsTrue(snap.TryWeakSuccessor(41, out res) && res == 41);

                Assert.IsFalse(snap.TryWeakSuccessor(42, out res));
                Assert.AreEqual(0, res);
            }


			[Test]
			public void Predecessor()
			{
				Assert.AreEqual(13, snap.Predecessor(15));
				Assert.AreEqual(15, snap.Predecessor(16));
				Assert.AreEqual(15, snap.Predecessor(17));
				Assert.AreEqual(17, snap.Predecessor(18));
			}


			[Test]
			public void Successor()
			{
				Assert.AreEqual(17, snap.Successor(15));
				Assert.AreEqual(17, snap.Successor(16));
				Assert.AreEqual(19, snap.Successor(17));
				Assert.AreEqual(19, snap.Successor(18));
			}


			[Test]
			public void WeakPredecessor()
			{
				Assert.AreEqual(15, snap.WeakPredecessor(15));
				Assert.AreEqual(15, snap.WeakPredecessor(16));
				Assert.AreEqual(17, snap.WeakPredecessor(17));
				Assert.AreEqual(17, snap.WeakPredecessor(18));
			}


			[Test]
			public void WeakSuccessor()
			{
				Assert.AreEqual(15, snap.WeakSuccessor(15));
				Assert.AreEqual(17, snap.WeakSuccessor(16));
				Assert.AreEqual(17, snap.WeakSuccessor(17));
				Assert.AreEqual(19, snap.WeakSuccessor(18));
			}


			[Test]
			[ExpectedException(typeof(NotSupportedException), ExpectedMessage="Indexing not supported for snapshots")]
			public void CountTo()
			{
				int j = snap.CountTo(15);
			}


			[Test]
			[ExpectedException(typeof(NotSupportedException), ExpectedMessage="Indexing not supported for snapshots")]
			public void Indexing()
			{
				int j = snap[4];
			}


			[Test]
			[ExpectedException(typeof(NotSupportedException), ExpectedMessage="Indexing not supported for snapshots")]
			public void Indexing2()
			{
				int j = snap.IndexOf(5);
			}


			[TearDown]
			public void Dispose()
			{
				tree = null;
				ic = null;
			}
		}



		[TestFixture]
		public class Single
		{
			private TreeSet<int> tree;

			private SCG.IComparer<int> ic;


			[SetUp]
			public void Init()
			{
				ic = new IC();
				tree = new TreeSet<int>(ic);
				for (int i = 0; i < 10; i++)
					tree.Add(2 * i + 1);
			}


			[Test]
			public void EnumerationWithAdd()
			{
				int[] orig = new int[] { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 };
				int i = 0;
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				foreach (int j in snap)
				{
					Assert.AreEqual(1 + 2 * i++, j);
					tree.Add(21 - j);
					Assert.IsTrue(snap.Check("M"), "Bad snap!");
					Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
					Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				}
			}


			[Test]
			public void Remove()
			{
				int[] orig = new int[] { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 };
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				tree.Remove(19);
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
			}


			[Test]
			public void RemoveNormal()
			{
				tree.Clear();
				for (int i = 10; i < 20; i++)
				{
					tree.Add(i);
					tree.Add(i + 10);
				}

				int[] orig = new int[] { 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 };
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				Assert.IsFalse(tree.Remove(-20));
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//No demote case, with move_item
				Assert.IsTrue(tree.Remove(20));
				Assert.IsTrue(tree.Check("T1"));
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsFalse(tree.Remove(20));

				//plain case 2
				tree.Snapshot();
				Assert.IsTrue(tree.Remove(14));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//case 1b
				Assert.IsTrue(tree.Remove(25));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//case 1c
				Assert.IsTrue(tree.Remove(29));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//1a (terminating)
				Assert.IsTrue(tree.Remove(10));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//2+1b
				Assert.IsTrue(tree.Remove(12));
				tree.Snapshot();
				Assert.IsTrue(tree.Remove(11));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//1a+1b
				Assert.IsTrue(tree.Remove(18));
				Assert.IsTrue(tree.Remove(13));
				Assert.IsTrue(tree.Remove(15));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//2+1c
				for (int i = 0; i < 10; i++)
					tree.Add(50 - 2 * i);

				Assert.IsTrue(tree.Remove(42));
				Assert.IsTrue(tree.Remove(38));
				Assert.IsTrue(tree.Remove(28));
				Assert.IsTrue(tree.Remove(40));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//
				Assert.IsTrue(tree.Remove(16));
				Assert.IsTrue(tree.Remove(23));
				Assert.IsTrue(tree.Remove(17));
				Assert.IsTrue(tree.Remove(19));
				Assert.IsTrue(tree.Remove(50));
				Assert.IsTrue(tree.Remove(26));
				Assert.IsTrue(tree.Remove(21));
				Assert.IsTrue(tree.Remove(22));
				Assert.IsTrue(tree.Remove(24));
				for (int i = 0; i < 48; i++)
					tree.Remove(i);

				//Almost empty tree:
				Assert.IsFalse(tree.Remove(26));
				Assert.IsTrue(tree.Remove(48));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");

				//Empty tree:
				Assert.IsFalse(tree.Remove(26));
				Assert.IsTrue(tree.Check("Normal test 1"), "Bad tree");
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
			}


			[Test]
			public void Add()
			{
				int[] orig = new int[] { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 };
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				tree.Add(10);
				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				tree.Add(16);
				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");

				//Promote+zigzig
				tree.Add(40);
				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				for (int i = 1; i < 4; i++)
					tree.Add(40 - 2 * i);

				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");

				//Zigzag:
				tree.Add(32);
				Assert.IsTrue(snap.Check("M"), "Bad snap!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
			}


			[Test]
			public void Clear()
			{
				int[] orig = new int[] { 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 };
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				tree.Clear();
				Assert.IsTrue(snap.Check("Snap"), "Bad snap!");
				Assert.IsTrue(tree.Check("Tree"), "Bad tree!");
				Assert.IsTrue(IC.eq(snap, orig), "Snap was changed!");
				Assert.AreEqual(0, tree.Count);
			}


			[Test]
			[ExpectedException(typeof(InvalidOperationException), ExpectedMessage="Cannot snapshot a snapshot")]
			public void SnapSnap()
			{
				TreeSet<int> snap = (TreeSet<int>)tree.Snapshot();

				snap.Snapshot();
			}


			[TearDown]
			public void Dispose()
			{
				tree = null;
				ic = null;
			}
		}



		[TestFixture]
		public class Multiple
		{
			private TreeSet<int> tree;

			private SCG.IComparer<int> ic;


			private bool eq(SCG.IEnumerable<int> me, int[] that)
			{
				int i = 0, maxind = that.Length - 1;

				foreach (int item in me)
					if (i > maxind || ic.Compare(item, that[i++]) != 0)
						return false;

				return true;
			}


			[SetUp]
			public void Init()
			{
				ic = new IC();
				tree = new TreeSet<int>(ic);
				for (int i = 0; i < 10; i++)
					tree.Add(2 * i + 1);
			}


			[Test]
			public void First()
			{
				TreeSet<int>[] snaps = new TreeSet<int>[10];

				for (int i = 0; i < 10; i++)
				{
					snaps[i] = (TreeSet<int>)(tree.Snapshot());
					tree.Add(2 * i);
				}

				for (int i = 0; i < 10; i++)
				{
					Assert.AreEqual(i + 10, snaps[i].Count);
				}

				snaps[5] = null;
				snaps[9] = null;
				GC.Collect();
				snaps[8].Dispose();
				tree.Remove(14);

				int[] res = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19 };
				int[] snap7 = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 17, 19 };
				int[] snap3 = new int[] { 0, 1, 2, 3, 4, 5, 7, 9, 11, 13, 15, 17, 19 };

				Assert.IsTrue(IC.eq(snaps[3], snap3), "Snap 3 was changed!");
				Assert.IsTrue(IC.eq(snaps[7], snap7), "Snap 7 was changed!");
				Assert.IsTrue(IC.eq(tree, res));
				Assert.IsTrue(tree.Check("B"));
				Assert.IsTrue(snaps[3].Check("B"));
				Assert.IsTrue(snaps[7].Check("B"));
			}


			[Test]
			public void CollectingTheMaster()
			{
				TreeSet<int>[] snaps = new TreeSet<int>[10];

				for (int i = 0; i < 10; i++)
				{
					snaps[i] = (TreeSet<int>)(tree.Snapshot());
					tree.Add(2 * i);
				}

				tree = null;
				GC.Collect();
				for (int i = 0; i < 10; i++)
				{
					Assert.AreEqual(i + 10, snaps[i].Count);
				}

				snaps[5] = null;
				snaps[9] = null;
				GC.Collect();
				snaps[8].Dispose();

				int[] snap7 = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 17, 19 };
				int[] snap3 = new int[] { 0, 1, 2, 3, 4, 5, 7, 9, 11, 13, 15, 17, 19 };

				Assert.IsTrue(IC.eq(snaps[3], snap3), "Snap 3 was changed!");
				Assert.IsTrue(IC.eq(snaps[7], snap7), "Snap 7 was changed!");
				Assert.IsTrue(snaps[3].Check("B"));
				Assert.IsTrue(snaps[7].Check("B"));
			}


			[TearDown]
			public void Dispose()
			{
				tree = null;
				ic = null;
			}
		}
	}




	namespace HigherOrder
	{
		internal class CubeRoot: IComparable<int>
		{
			private int c;


			internal CubeRoot(int c) { this.c = c; }


			public int CompareTo(int that) { return c - that * that * that; }
            public bool Equals(int that) { return c == that * that * that; }
        }



        class Interval: IComparable<int>
		{
			private int b, t;


			internal Interval(int b, int t) { this.b = b; this.t = t; }


			public int CompareTo(int that) { return that < b ? 1 : that > t ? -1 : 0; }
            public bool Equals(int that) { return that >= b && that <= t; }
        }



        [TestFixture]
		public class Simple
		{
			private TreeSet<int> tree;

			private SCG.IComparer<int> ic;


			[SetUp]
			…