public void Insert(string word)
{
if (string.Compare(word, _previousWord, StringComparison.OrdinalIgnoreCase) <= 0)
{
throw new Exception($"We expect the words to be sorted. But we received {_previousWord} followed by {word}");
}
int commonPrefix;
for (commonPrefix = 0; commonPrefix < Math.Min(word.Length, _previousWord.Length); commonPrefix++)
{
if (word[commonPrefix] != _previousWord[commonPrefix])
{
break;
}
}
Minimize(commonPrefix);
var node = _uncheckedNodes.Count == 0 ? Root : _uncheckedNodes.Peek().Item3;
foreach (var letter in word.Skip(commonPrefix))
{
var nextNode = new DawgNode();
node.Children[letter] = nextNode;
_uncheckedNodes.Push(new Tuple <DawgNode, char, DawgNode>(node, letter, nextNode));
node = nextNode;
}
node.TerminalNode = true;
_previousWord = word;
}
internal Dawg(IEnumerable <string> words)
{
var builder = new DawgBuilder();
foreach (var word in words)
{
builder.Insert(word);
}
var root = builder.Finish();
var allNodes = new List <DawgNode>();
var allChars = new HashSet <char>();
int low = 0, high = 0;
var totalChildCount = root.Traversal(ref low, ref high, allNodes, allChars);
Func <int, int> realIndex = x => - low + (x < 0 ? x : x - 1);
Characters = allChars.OrderBy(character => character).ToArray();
Edges = new int[totalChildCount];
EdgeCharacter = new ushort[totalChildCount];
FirstChildIndex = new int[high - low];
RootNodeIndex = realIndex(root.Id);
TerminalCount = -low;
var characterIndex = Characters.Select((character, i) => new KeyValuePair <char, ushort>(character, (ushort)i)).ToDictionary(x => x.Key, x => x.Value);
var orderedNodes = new DawgNode[allNodes.Count];
foreach (var node in allNodes)
{
orderedNodes[realIndex(node.Id)] = node;
}
var edgeIndex = 0;
foreach (var node in orderedNodes)
{
FirstChildIndex[realIndex(node.Id)] = edgeIndex;
foreach (var child in node.SortedChildren)
{
Edges[edgeIndex] = realIndex(child.Value.Id);
EdgeCharacter[edgeIndex] = characterIndex[child.Key];
edgeIndex++;
}
}
}