public List <List <int> > GetValuesByBottomUpLevel(NaryTreeNode root)//BFS traversal
{
List <List <int> > result = new List <List <int> >();
if (root != null)
{
Queue <NaryTreeNode> queue = new Queue <NaryTreeNode>();
queue.Enqueue(root);
while (queue.Count > 0)
{
int currCount = queue.Count;
List <int> currLevelQ = new List <int>();
for (int i = 0; i < currCount; i++)
{
NaryTreeNode node = queue.Dequeue();
currLevelQ.Add(node.Value);
if (root.Children != null)
{
foreach (NaryTreeNode child in root.Children)
{
queue.Enqueue(child);
}
}
}
result.Add(currLevelQ);
}
}
result.Reverse(); //bottom up
return(result);
}
public List <int> RightSideViewByLevel(NaryTreeNode root)//BFS traversal
{
List <int> result = new List <int>();
if (root != null)
{
Queue <NaryTreeNode> queue = new Queue <NaryTreeNode>();
queue.Enqueue(root);
while (queue.Count > 0)
{
int currCount = queue.Count;
int rightMostElement = 0;
for (int i = 0; i < currCount; i++)
{
NaryTreeNode node = queue.Dequeue();
rightMostElement = node.Value;
if (root.Children != null)
{
foreach (NaryTreeNode child in root.Children)
{
queue.Enqueue(child);
}
}
}
result.Add(rightMostElement);
}
}
return(result);
}
//559. Maximum Depth of N-ary Tree
public int MaxDepth(NaryTreeNode root)
{
if (root != null)
{
MaxDepthHelper(root, 1);
}
return(result);
}
public void MaxDepthHelper(NaryTreeNode root, int height)
{
if (root.Children == null || root.Children.Count == 0)
{
result = Math.Max(result, height);
}
else
{
if (root.Children != null || root.Children.Count > 0)
{
foreach (NaryTreeNode child in root.Children)
{
MaxDepthHelper(child, height + 1);
}
}
}
}
public List <List <int> > GetValuesByLevelInZigZagOrder(NaryTreeNode root)//BFS traversal
{
List <List <int> > result = new List <List <int> >();
if (root != null)
{
Queue <NaryTreeNode> queue = new Queue <NaryTreeNode>();
queue.Enqueue(root);
bool reverse = false;
while (queue.Count > 0)
{
int currCount = queue.Count;
List <int> currLevelQ = new List <int>();
for (int i = 0; i < currCount; i++)
{
NaryTreeNode node = queue.Dequeue();
currLevelQ.Add(node.Value);
if (root.Children != null)
{
foreach (NaryTreeNode child in root.Children)
{
queue.Enqueue(child);
}
}
}
if (reverse)
{
currLevelQ.Reverse();
}
reverse = !reverse;
result.Add(currLevelQ);
}
}
return(result);
}