public String Test(String input)
{
Node head = Node.Make(JsonConvert.DeserializeObject <Int32?[]>(input));
Node result = this.Flatten(head);
return(JsonConvert.SerializeObject(Node.Make(result)));
}
public Node Flatten(Node head)
{
Node current = head;
var next = new Stack <Node>();
while (current != null)
{
if (current.child != null)
{
if (current.next != null)
{
next.Push(current.next);
}
current.next = current.child;
current.child = null;
current.next.prev = current;
current = current.next;
continue;
}
if ((current.next == null) && (next.Count > 0))
{
current.next = next.Pop();
current.next.prev = current;
current = current.next;
continue;
}
current = current.next;
}
return(head);
}
public static IEnumerable <Int32?> Make(Node node)
{
var levels = new List <IList <Int32?> >();
Int32 indentation = 0;
var currentLevel = new List <Int32?>();
while (node != null)
{
currentLevel.Add(node.val);
if (node.child != null)
{
List <Int32?> childLevel = MultilevelDoublyLinkedListNode.Make(node.child).ToList();
childLevel.InsertRange(0, Enumerable.Repeat <Int32?>(null, indentation));
levels.Insert(0, childLevel);
}
node = node.next;
indentation++;
}
levels.Insert(0, currentLevel);
var result = new List <Int32?>();
foreach (IList <Int32?> level in levels)
{
result.AddRange(level);
result.Add(null);
}
return(result.Take(1 + result.FindLastIndex(value => value != null)));
}
public void Test(String input)
{
// ARRANGE
var valuesIn = JsonConvert.DeserializeObject <Int32?[]>(input);
// ACT
Node head = Node.Make(valuesIn);
IEnumerable <Int32?> valuesOut = Node.Make(head);
// ASSERT
String output = JsonConvert.SerializeObject(valuesOut);
Assert.That(output, Is.EqualTo(input));
}
public static Node Make([NotNull] IEnumerable <Int32?> values)
{
if (values == null)
{
throw new ArgumentNullException(nameof(values));
}
Int32?[] enumerable = values as Int32?[] ?? values.ToArray();
Int32 length = enumerable.Length;
if (length == 0)
{
return(null);
}
if (enumerable[0] == null)
{
throw new ArgumentException("The value of index zero cannot be null.", nameof(values));
}
Int32 currentLevel = 0;
Boolean newLevel = false;
var levels = new List <IList <Int32?> >();
foreach (Int32?value in enumerable)
{
if (levels.Count <= currentLevel)
{
levels.Add(new List <Int32?>());
}
levels[currentLevel].Add(value);
if ((value == null) && !newLevel)
{
currentLevel++;
newLevel = true;
continue;
}
if ((value != null) && newLevel)
{
newLevel = false;
}
}
Node head = null;
Node levelHead = null;
foreach (IList <Int32?> level in levels)
{
Node parent = levelHead;
levelHead = null;
Node previous = null;
foreach (Int32?value in level)
{
if (value == null)
{
parent = parent?.next;
continue;
}
var current = new Node(value.Value)
{
prev = previous
};
if (previous != null)
{
previous.next = current;
}
previous = current;
if (parent != null)
{
parent.child = current;
parent = null;
}
if (head == null)
{
head = current;
}
if (levelHead == null)
{
levelHead = current;
}
}
}
return(head);
}
