public static IList <int> PreOrderNonRecursive(LeetCode589Node root)
{
Stack <LeetCode589Node> stack = new Stack <LeetCode589Node>();
IList <int> results = new List <int>();
if (root == null)
{
return(results);
}
stack.Push(root);
while (stack.Count != 0)
{
var node = stack.Pop();
results.Add(node.val);
var temp = (List <LeetCode589Node>)node.children;
temp.Reverse();
foreach (var child in temp)
{
stack.Push(child);
}
}
return(results);
}
private static void PreOrder(LeetCode589Node root)
{
if (root == null)
{
return;
}
results.Add(root.val);
foreach (var child in root.children)
{
PreOrder(child);
}
}
public static IList <int> PreOrderTraversal(LeetCode589Node root)
{
PreOrder(root);
return(results);
}