public List <int> PreOrderLoop(MultiTreeNode root)
{
List <int> vals = new List <int>();
Stack <MultiTreeNode> stack = new Stack <MultiTreeNode>();
stack.Push(root);
while (stack.Count > 0)
{
MultiTreeNode n = stack.Pop();
vals.Add(n.Val);
List <MultiTreeNode> nodes = new List <MultiTreeNode>();
MultiTreeNode child = n.LeftChild;
while (child != null)
{
nodes.Add(child);
child = child.RightSibling;
}
for (int i = nodes.Count - 1; i >= 0; i--)
{
stack.Push(nodes[i]);
}
}
return(vals);
}
public List <int> PostOrder(MultiTreeNode root)
{
List <int> vals = new List <int>();
PostTraverse(root, vals);
return(vals);
}
private void PostTraverse(MultiTreeNode n, List <int> vals)
{
MultiTreeNode child = n.LeftChild;
while (child != null)
{
PostTraverse(child, vals);
child = child.RightSibling;
}
vals.Add(n.Val);
}
private static void MultiTreeTest()
{
MultiTreeNode root = new MultiTreeNode()
{
Val = 1
};
root.LeftChild = new MultiTreeNode()
{
Val = 2
};
root.LeftChild.RightSibling = new MultiTreeNode()
{
Val = 3
};
root.LeftChild.LeftChild = new MultiTreeNode()
{
Val = 4
};
root.LeftChild.LeftChild.RightSibling = new MultiTreeNode()
{
Val = 5
};
root.LeftChild.RightSibling.LeftChild = new MultiTreeNode()
{
Val = 6
};
root.LeftChild.RightSibling.LeftChild.RightSibling = new MultiTreeNode()
{
Val = 7
};
MultiTree tree = new MultiTree();
var vals = tree.PreOrderLoop(root);
Console.WriteLine("Pre Order Loop: " + string.Join(',', vals));
vals = tree.PostOrderLoop(root);
Console.WriteLine("Post Order Loop: " + string.Join(',', vals));
vals = tree.PreOrder(root);
Console.WriteLine("Pre Order: " + string.Join(',', vals));
vals = tree.PostOrder(root);
Console.WriteLine("Post Order: " + string.Join(',', vals));
}
public List <int> PostOrderLoop(MultiTreeNode root)
{
List <int> vals = new List <int>();
Stack <MultiTreeNode> stack = new Stack <MultiTreeNode>();
MultiTreeNode cur = root;
while (stack.Count > 0 || cur != null)
{
while (cur != null)
{
stack.Push(cur);
cur = cur.LeftChild;
}
cur = stack.Pop();
vals.Add(cur.Val);
cur = cur.RightSibling;
}
return(vals);
}