private void DFSHelper(char[,] matrix, int r, int c, int m, int n, bool[,] visited, TrieNode node, string prefix, IList <string> results)
{
if (!visited[r, c])
{
visited[r, c] = true;
string s = prefix + matrix[r, c];
TrieNode match = node.Search3(s);
if (match != null)
{
if (match.LeafNode)
{
results.Add(s);
}
//string before = s;
IList <IList <int> > neighbors = WordSearchHelper.GetValidNeighbors(matrix, r, c, m, n, visited);
foreach (var neighbor in neighbors)
{
DFSHelper(matrix, neighbor[0], neighbor[1], m, n, visited, node, s, results);
//sb = new StringBuilder(before);
}
}
visited[r, c] = false;
}
}
private bool WordExistsHelper(char[,] matrix, int r, int c, int m, int n, string word, int index, bool[,] visited)
{
if (index == word.Length)
{
return(true);
}
if (matrix[r, c] == word[index])
{
visited[r, c] = true;
if (index == word.Length - 1)
{
return(true);
}
IList <IList <int> > neighbors = WordSearchHelper.GetValidNeighbors(matrix, r, c, m, n, visited);
foreach (var neighbor in neighbors)
{
bool success = WordExistsHelper(matrix, neighbor[0], neighbor[1], m, n, word, index + 1, visited);
if (success)
{
return(true);
}
}
visited[r, c] = false;
}
return(false);
}