public int[] encode(TNode tree)
{
int n = TNode.CountVertices(tree);
if (n <= 2)
{
return(null);
}
TNode treeToDecode = tree;
int[] result = new int[n - 2];
for (int x = 0; x < n - 2; x++)
{
TNode lowestNode = treeToDecode.FindLowestLeaf();
TNode nearestNeighbor = lowestNode.Parent == null ? lowestNode.Children[0] : lowestNode.Parent;
result[x] = (int)nearestNeighbor.label;
if (nearestNeighbor.Parent == lowestNode)
{
nearestNeighbor.Parent = null;
}
else
{
nearestNeighbor.RemoveChild(lowestNode);
}
if (lowestNode.Parent != null)
{
lowestNode.Parent.RemoveChild(lowestNode);
}
else if (lowestNode == treeToDecode)
{
treeToDecode = treeToDecode.Children[0];
}
}
return(result);
}