public List <List <WordPathNode> > FindWords()
{
var results = new List <List <WordPathNode> >();
var visitorTracker = new HashSet <int>();
var foundWords = new HashSet <DigitalTreeNode>();
for (int row = 0; row < BoggleBoard.RowCount; row++)
{
for (int col = 0; col < BoggleBoard.ColumnCount; col++)
{
var currChar = BoggleBoard.GetCharacter(row, col);
if (!WordDictionary.RootTreeNode.NextNodes.ContainsKey(currChar))
{
continue;
}
var startPath = new List <WordPathNode>();
startPath.Add(new WordPathNode(row, col, currChar));
visitorTracker.Add(GetIndex(row, col));
// Find all the words that start with this letter
FindWords(row, col, results, WordDictionary.RootTreeNode.NextNodes[currChar], startPath, visitorTracker, foundWords);
visitorTracker.Remove(GetIndex(row, col));
}
}
return(results);
}
public List <List <WordPathNode> > FindWords(int currRow, int currCol,
List <List <WordPathNode> > results, DigitalTreeNode currNode, List <WordPathNode> currPath, HashSet <int> visitorTracker, HashSet <DigitalTreeNode> foundWords)
{
if (currNode.IsCompleteWord && !foundWords.Contains(currNode))
{
if (currPath.Count >= MinimumWordLength)
{
AddPathToList(results, currPath);
}
// Keep track of found words so we don't add duplicates
foundWords.Add(currNode);
}
foreach (int nextIndex in GetNeighbors(currRow, currCol))
{
if (visitorTracker.Contains(nextIndex))
{
continue; // We've already visited this node
}
int nextRow = GetRow(nextIndex);
int nextCol = GetColumn(nextIndex);
char nextChar = BoggleBoard.GetCharacter(nextRow, nextCol);
DigitalTreeNode nextNode = null;
if (!currNode.NextNodes.ContainsKey(nextChar))
{
continue;
}
nextNode = currNode.NextNodes[nextChar];
// TODO: Account for the "U" that follows "Q" on the "QU" dices
currPath.Add(new WordPathNode(nextRow, nextCol, nextChar));
visitorTracker.Add(nextIndex);
// Recurse into neighbors with viable prefixes
FindWords(GetRow(nextIndex), GetColumn(nextIndex), results, nextNode, currPath, visitorTracker, foundWords);
visitorTracker.Remove(nextIndex);
currPath.RemoveAt(currPath.Count - 1);
}
return(results);
}
static void Main(string[] args)
{
var wordDictionary = new WordDictionary();
wordDictionary.LoadWords(Assembly.GetExecutingAssembly().GetManifestResourceStream("App.Problems.BoggleWords.Dictionary.txt"));
// Have fun with it and try different board sizes
var boggleBoard = new BoggleBoard(4, 4);
boggleBoard.Print();
Console.WriteLine();
var finder = new BoggleWordFinder(boggleBoard, wordDictionary);
var results = finder.FindWords();
Console.WriteLine("Found {0} words", results.Count);
Console.WriteLine();
int index = 1;
foreach (var pathList in results)
{
Console.Write("Word {0} : ", index++);
foreach (var wordPathNode in pathList)
{
Console.Write(wordPathNode.Character);
}
Console.Write(" ");
foreach (var wordPathNode in pathList)
{
Console.Write("({0}, {1}) = {2} ", wordPathNode.Row, wordPathNode.Column, wordPathNode.Character);
}
Console.WriteLine();
}
}
public BoggleWordFinder(BoggleBoard boggleBoard, WordDictionary wordDictionary)
{
BoggleBoard = boggleBoard;
WordDictionary = wordDictionary;
MinimumWordLength = 3;
}