public static void Main(string[] args)
{
System.Console.WriteLine("LinkList Sample");
SinglyLinkedList <int> primeNumbers = new SinglyLinkedList <int>();
// first we'll add the middle element. Then try the AddToFront with 3 and then try the AddToBack with 7
// generating the final sequence as 3, 5, 7
primeNumbers.AddToFront(5);
primeNumbers.AddToFront(3);
primeNumbers.AddToBack(7);
primeNumbers.AddToBack(9);
primeNumbers.AddToBack(8);
primeNumbers.AddToBack(7);
primeNumbers.Remove(8);
primeNumbers.RemoveLast();
PrintHelpers.PrintFromNode(primeNumbers.Head);
System.Console.WriteLine("Stack Sample: ");
PostfixCalculator postfixCalculator = new PostfixCalculator();
int result = postfixCalculator.calculate("5 6 7 * + 1 -");
System.Console.WriteLine($"The postfix expression result is: {result}");
System.Console.WriteLine("Binary Search Tree Sample:");
BinaryTree <int> binaryTree = new BinaryTree <int>();
binaryTree.Add(3);
binaryTree.Add(7);
binaryTree.Add(5);
binaryTree.Add(4);
binaryTree.Add(6);
binaryTree.Add(8);
binaryTree.Add(11);
binaryTree.Add(1);
System.Console.WriteLine($"Contains 5: {binaryTree.Contains(5)}");
System.Console.WriteLine($"Contains 6: {binaryTree.Contains(6)}");
System.Console.WriteLine($"Contains 1: {binaryTree.Contains(1)}");
System.Console.WriteLine($"Remove 9 op result: {binaryTree.Remove(9)}");
System.Console.WriteLine($"Remove 7 op result: {binaryTree.Remove(7)}");
System.Console.WriteLine("Traversal Outputs:");
Traversals <int> traversals = new Traversals <int>();
IReadOnlyCollection <int> preOrder = traversals.PreorderTraversal(binaryTree);
IReadOnlyCollection <int> inOrder = traversals.InorderTraversal(binaryTree);
IReadOnlyCollection <int> postOrder = traversals.PostorderTraversal(binaryTree);
System.Console.WriteLine($"Postorder: {string.Join(", ", preOrder)}");
System.Console.WriteLine($"Inorder: {string.Join(", ", inOrder)}");
System.Console.WriteLine($"Postorder: {string.Join(", ", postOrder)}");
}