//------------------- HELPER METHODS ---------------------
//gets the next item in an in-order search.
private T inOrderNext()
{
BinaryNode <T> last = my_element_stack.pop();
if (last.stack_turn == 0) //first time off the stack
{
//put last back on the stack and mark as visited
my_element_stack.push(last);
last.stack_turn++;
if (last.left != null)
{
my_element_stack.push(last.left);
}
return(inOrderNext());
}
else //stack_turn == 1
{
if (last.right != null)
{
my_element_stack.push(last.right);
}
last.stack_turn = 0;
my_previous = my_current;
my_current = last;
return(last.value);
}
}
//------------------- HELPER METHODS ----------------------
private void addStackItems(BasicStack <DSString> the_stack)
{
for (int i = 0; i < 10; i++)
{
the_stack.push(new DSString(i.ToString()));
}
}
/// <summary>
/// Sets up the iterate with a traversal method, an initial node to traverse from and a link
/// to the parent binary search tree.
/// </summary>
/// <param name="the_traversal_method">the method of traversing the tree.</param>
/// <param name="the_parent_root">the root of the tree.</param>
/// <param name="the_parent">link to the parent tree itself.</param>
public BSTIterator(GraphTraversals the_traversal_method, BinaryNode <T> the_source_node, BinarySearchTree <T> the_parent)
{
my_traversal_method = the_traversal_method;
my_parent = the_parent;
//prepare stack for traversal
my_element_stack = new Stack <BinaryNode <T> >(my_parent.size());
my_element_queue = new Queue <BinaryNode <T> >();
//add the first element if it is there
if (my_parent.root != null)
{
my_element_stack.push(the_source_node);
my_element_queue.enqueue(the_source_node);
}
}
private void testClear(BasicStack <DSString> the_stack)
{
//make sure size() and isEmpty() are correct before clear
Assert.AreEqual(false, the_stack.isEmpty());
Assert.AreEqual(10, the_stack.size());
//after clearing
the_stack.clear();
Assert.AreEqual(true, the_stack.isEmpty());
Assert.AreEqual(0, the_stack.size());
//after readding and clearing
the_stack.push(new DSString("13"));
Assert.AreEqual(false, the_stack.isEmpty());
Assert.AreEqual(1, the_stack.size());
}
private void testSize(BasicStack <DSString> the_stack)
{
//check after initial insertion
Assert.AreEqual(10, the_stack.size());
//check after removal
the_stack.pop();
Assert.AreEqual(9, the_stack.size());
//check after addition
the_stack.push(new DSString("13"));
Assert.AreEqual(10, the_stack.size());
//check after removing all
the_stack.clear();
Assert.AreEqual(0, the_stack.size());
}
private void testIsEmpty(BasicStack <DSString> the_stack)
{
//check while not empty
Assert.IsFalse(the_stack.isEmpty());
//after empty
the_stack.clear();
Assert.IsTrue(the_stack.isEmpty());
//after re-addition
the_stack.push(new DSString("1"));
Assert.IsFalse(the_stack.isEmpty());
//after empty again
the_stack.clear();
Assert.IsTrue(the_stack.isEmpty());
}
private void testPop(BasicStack <DSString> the_stack)
{
//make sure the ordering is secure
Assert.AreEqual("9", the_stack.pop().value);
Assert.AreEqual("8", the_stack.pop().value);
Assert.AreEqual("7", the_stack.pop().value);
//add an item after removing
the_stack.push(new DSString("13"));
//check ordering
Assert.AreEqual("13", the_stack.pop().value);
Assert.AreEqual("6", the_stack.pop().value);
Assert.AreEqual("5", the_stack.pop().value);
Assert.AreEqual("4", the_stack.pop().value);
Assert.AreEqual("3", the_stack.pop().value);
Assert.AreEqual("2", the_stack.pop().value);
Assert.AreEqual("1", the_stack.pop().value);
Assert.AreEqual("0", the_stack.pop().value);
}
private void testContains(BasicStack <DSString> the_stack)
{
//make sure all items are matched inside
Assert.AreEqual(true, the_stack.contains(new DSString("0")));
Assert.AreEqual(true, the_stack.contains(new DSString("1")));
Assert.AreEqual(true, the_stack.contains(new DSString("2")));
Assert.AreEqual(true, the_stack.contains(new DSString("3")));
Assert.AreEqual(true, the_stack.contains(new DSString("4")));
Assert.AreEqual(true, the_stack.contains(new DSString("5")));
Assert.AreEqual(true, the_stack.contains(new DSString("6")));
Assert.AreEqual(true, the_stack.contains(new DSString("7")));
Assert.AreEqual(true, the_stack.contains(new DSString("8")));
Assert.AreEqual(true, the_stack.contains(new DSString("9")));
//check after removal
the_stack.pop();
Assert.AreEqual(false, the_stack.contains(new DSString("9")));
//check after adding
the_stack.push(new DSString("13"));
Assert.AreEqual(true, the_stack.contains(new DSString("13")));
//check after removing all
the_stack.clear();
Assert.AreEqual(false, the_stack.contains(new DSString("13")));
Assert.AreEqual(false, the_stack.contains(new DSString("0")));
Assert.AreEqual(false, the_stack.contains(new DSString("1")));
Assert.AreEqual(false, the_stack.contains(new DSString("2")));
Assert.AreEqual(false, the_stack.contains(new DSString("3")));
Assert.AreEqual(false, the_stack.contains(new DSString("4")));
Assert.AreEqual(false, the_stack.contains(new DSString("5")));
Assert.AreEqual(false, the_stack.contains(new DSString("6")));
Assert.AreEqual(false, the_stack.contains(new DSString("7")));
Assert.AreEqual(false, the_stack.contains(new DSString("8")));
Assert.AreEqual(false, the_stack.contains(new DSString("9")));
}
