public static void Main()
{
// Create a new doubly linked list of type int.
DoublyLinkedList <int> dll = new DoublyLinkedList <int>();
Console.WriteLine("Populate new doubly linked list that is NOT a palindrome...");
dll.AddFirst(3);
dll.AddLast(5);
dll.AddLast(7);
dll.AddLast(9);
Console.WriteLine("Print:");
dll.Print();
Console.WriteLine("Print Reverse:");
dll.PrintReverse();
// The IsPalindrome contains 3 methods:
// IsPalindrome: O(2n)
// ReverseAndCopy: O(n), with O(n) space.
// IsEqual: O(n)
// Runtime for IsPalindrome method execution: O(2n) -> O(n)
// with O(n) extra memory.
// Still trying to work in generics, only accepts type int right now.
Console.WriteLine($"Is linked list a palindrome: {dll.IsPalindrome(dll.Head)}");
Console.WriteLine();
Console.WriteLine("Clear linked list.");
dll.Clear();
Console.WriteLine($"Linked list is Empty: {dll.IsEmpty()}");
Console.WriteLine();
Console.WriteLine("Populate new doubly linked list that IS a palindrome...");
dll.AddFirst(3);
dll.AddLast(5);
dll.AddLast(7);
dll.AddLast(5);
dll.AddLast(3);
Console.WriteLine("Print:");
dll.Print();
Console.WriteLine("Print Reverse:");
dll.PrintReverse();
Console.WriteLine($"Is linked list a palindrome: {dll.IsPalindrome(dll.Head)}");
}
public static void Main()
{
// Declare new doubly linked list of type int, using Generics<T>.
// Big Oh notated below in Main.
DoublyLinkedList <int> ll = new DoublyLinkedList <int>();
Console.WriteLine("Populate new doubly linked list of type int.");
// AddFirst: O(1)
ll.AddFirst(3);
// Create new node to insert.
var n = new Node <int>(7);
// AddLast by node, O(1).
ll.AddLast(n);
// Insert 5 before the 7 node, O(n).
ll.AddBefore(n, 5);
// AddLast by value, O(1).
ll.AddLast(9);
Console.WriteLine("Print:");
ll.Print(); // O(n)
Console.WriteLine("Print Reverse:");
// Print Reverse: O(n)
ll.PrintReverse();
Console.WriteLine("Remove nodes using RemoveFirst, RemoveLast, Remove(value) methods.");
ll.Remove(7); // Remove by value (search): O(n)
ll.Print();
ll.RemoveFirst(); // O(1)
ll.Print();
ll.RemoveLast(); // O(1)
ll.Print();
ll.Clear(); // O(1)
Console.WriteLine("Clear linked list.");
Console.WriteLine($"Linked list is Empty: {ll.IsEmpty()}"); // O(1)
// The Upshot: Doubly Linked Lists improve all operations at Tail from O(n) to O(1).
// Still O(n) to search or print, methods requiring complete or partial iteration.
// I used a Count variable, unlike the single list, because they improve the code.
}
public static void Main()
{
// Declare new doubly linked list of type int, using Generics<T>.
// Big Oh notated below in Main.
DoublyLinkedList <int> ll = new DoublyLinkedList <int>();
Console.WriteLine("Populate new linked list using AddFirst, AddLast and AddBefore.");
// O(1)
ll.AddFirst(3);
// Create new node to insert.
var n = new Node <int>(7);
// AddLast by node, O(1).
ll.AddLast(n);
// Insert 5 before the 7 node, O(n).
ll.AddBefore(n, 5);
// AddLast by value, O(1).
ll.AddLast(9);
Console.WriteLine("Print:");
ll.Print(); // O(n)
Console.WriteLine("Print Reverse:");
// Print Reverse
ll.PrintReverse(); // O(n)
Console.WriteLine("Remove nodes using RemoveFirst, RemoveLast, Remove(value) methods.");
ll.Remove(7); // O(n)
ll.Print();
ll.RemoveFirst(); // O(1)
ll.Print();
ll.RemoveLast(); // O(1)
ll.Print();
ll.Clear(); // O(1)
Console.WriteLine("Clear linked list.");
Console.WriteLine($"Linked list is Empty: {ll.IsEmpty()}"); // O(1)
}