// https://leetcode.com/discuss/interview-question/632709/Facebook-Interview-Question
public void BinaryTreePreorderIteratorTest()
{
var root = TreeNodeUtilities.GetTree("1,2,3,4,5,6,7,8,9,10");
var iterator = new PreorderIterator(root);
while (iterator.HasNext())
{
Console.Write($"{iterator.Next().val}, ");
}
}
static void UsingIteratorOutOfAggregates()
{
Tree tree = new Tree();
tree.InitData();
BTIterator preorderIterator = new PreorderIterator(tree);
BTIterator inorderIterator = new InorderIterator(tree);
BTIterator postorderIterator = new PostorderIterator(tree);
Print(preorderIterator);
Print(inorderIterator);
Print(postorderIterator);
}