public void RemovingFromAnEmptyBalancedTreeShouldThrowException()
{
BalancedTree <int> tree = new BalancedTree <int>();
Assert.IsTrue(tree.IsEmpty, "Tree is empty");
_ = Assert.Throws(typeof(TreeUnderflowException), () => tree.Remove(42), "Removing from an empty tree should throw exception");
}
public void RemovingAValueThatDoesNotExistShouldReturnFalse()
{
BalancedTree <int> tree = new BalancedTree <int>();
tree.Add(42);
Assert.IsFalse(tree.IsEmpty, "Tree is not empty");
Assert.IsFalse(tree.Remove(0), "Should not have been able to remove value not in the tree");
}
public void BalancedTree_RemoveTest()
{
var dictionary = CreateRandomDictionary(2000);
var tree = new BalancedTree<int, string>(17, dictionary);
var keys = dictionary.Keys.ToList();
foreach (var key in keys)
{
dictionary.Remove(key);
tree.Remove(key);
Assert.IsTrue(tree.SequenceEqual(dictionary.OrderBy(kvp => kvp.Key)));
}
Assert.IsFalse(tree.Any());
}
public void TestRemoval()
{
List <int> data = new List <int>
{
9, 5, 10, 0, 6, 11, -1, 1, 2
};
BalancedTree tree = new BalancedTree();
foreach (int datum in data)
{
tree.Insert(datum);
}
Assert.IsTrue(tree.PreOrder() == "910-15261011");
tree.Remove(10);
string result = tree.PreOrder();
Assert.IsTrue(result == "10-1952611");
}
public void RemovingAValueThatExistsShouldMaintainBalanceAndReturnTrue()
{
BalancedTree <int> tree = new BalancedTree <int>();
tree.Add(42);
// remove the root node - should return true and make the tree empty
Assert.IsTrue(tree.Remove(42), "Should be able to remove 42");
Assert.IsTrue(tree.IsEmpty, "Tree should be empty again");
tree.Add(42);
tree.Add(17);
tree.Add(0);
tree.Add(213401);
tree.Add(-1);
tree.Add(9);
// tree should now look like this:
// 42
// / \
// 17 0
// / \ /
// 213401 9 -1
Assert.IsFalse(tree.IsEmpty, "Tree is not empty");
Assert.AreEqual(6, tree.Size(), "Tree should have six nodes");
Assert.AreEqual(2, tree.Height(), "Tree should have height of 2");
Assert.AreEqual("42, 17, 213401, 9, 0, -1", tree.ToString(), "Tree should have comma separated list of values");
// simple case - remove a leaf
Assert.IsTrue(tree.Remove(-1), "Should have been able to remove 9");
Assert.IsFalse(tree.IsEmpty, "Tree is not empty");
Assert.AreEqual(5, tree.Size(), "Tree should have five nodes");
Assert.AreEqual(2, tree.Height(), "Tree should have height of 2");
Assert.AreEqual("42, 17, 213401, 9, 0", tree.ToString(), "Tree should have comma separated list of values");
// tree should now look like this:
// 42
// / \
// 17 0
// / \
// 213401 9
// remove 213401 - should move 9 to the left child of 17
Assert.IsTrue(tree.Remove(213401), "Should have been able to remove 213401");
// tree should now look like this:
// 42
// / \
// 17 0
// /
// 9
Assert.IsFalse(tree.IsEmpty, "Tree is not empty");
Assert.AreEqual(4, tree.Size(), "Tree should have four nodes");
Assert.AreEqual(2, tree.Height(), "Tree should have height of 2");
Assert.AreEqual("42, 17, 9, 0", tree.ToString(), "Tree should have comma separated list of values");
// add a few more nodes back into the tree and remove a node with two subtrees
tree.Add(-1);
tree.Add(69);
tree.Add(213401);
// tree should now look like this:
// 42
// / \
// 17 0
// / \ / \
// 9 69 -1 213401
Assert.IsTrue(tree.Remove(17), "Should have been able to remove 17");
// tree should now look like this:
// 42
// / \
// 69 0
// / / \
// 9 -1 213401
Assert.IsFalse(tree.IsEmpty, "Tree is not empty");
Assert.AreEqual(6, tree.Size(), "Tree should have six nodes");
Assert.AreEqual(2, tree.Height(), "Tree should have height of 2");
Assert.AreEqual("42, 69, 9, 0, -1, 213401", tree.ToString(), "Tree should have comma separated list of values");
}
