private static string DecodeText(CombinedNode tree, string encodedText)
{
var result = "";
var offset = 0;
INode currentNode = tree;
while (offset < encodedText.Length)
{
if (currentNode is CombinedNode combinedNode)
{
if (encodedText[offset] == '0')
{
currentNode = combinedNode.LHS;
}
else
{
currentNode = combinedNode.RHS;
}
}
if (currentNode is LeafNode leafNode)
{
result += leafNode.Key;
currentNode = tree;
}
offset++;
}
return(result);
}
private static CombinedNode BuildTree(IEnumerable <LeafNode> lettersByFrequency)
{
var leafQueue = new Queue <LeafNode>();
var combinedQueue = new Queue <CombinedNode>();
foreach (var item in lettersByFrequency)
{
leafQueue.Enqueue(item);
}
while (leafQueue.Count() + combinedQueue.Count() > 1)
{
var lhs = GetLowestItem(leafQueue, combinedQueue);
var rhs = GetLowestItem(leafQueue, combinedQueue);
var combinedNode = new CombinedNode(lhs, rhs);
combinedQueue.Enqueue(combinedNode);
}
return(combinedQueue.Dequeue());
}
