void Recur(char[,] board, Trie tr, int curi, int curj, bool[,] map, int maxm, int maxn, List<string> re, string str)
{
if (curi >= maxm || curi < 0 || curj >= maxn || curj < 0 || map[curi, curj])
return;
string newstr = str + board[curi, curj];
if (!tr.StartsWith(newstr))
return;
if (tr.Search(newstr) && !re.Contains(newstr))
{
re.Add(newstr);
}
map[curi, curj] = true;
Recur(board, tr, curi + 1, curj, map, maxm, maxn, re, newstr);
Recur(board, tr, curi - 1, curj, map, maxm, maxn, re, newstr);
Recur(board, tr, curi, curj + 1, map, maxm, maxn, re, newstr);
Recur(board, tr, curi, curj - 1, map, maxm, maxn, re, newstr);
map[curi, curj] = false;
return;
}
public void TestTrieWord()
{
Trie t = new Trie();
t.Insert("hello");
t.Insert("he");
t.Insert("haw");
t.Insert("match");
t.Insert("yesterday");
Assert.IsTrue(t.Search("he"));
Assert.IsTrue(t.Search("haw"));
Assert.IsFalse(t.Search("mated"));
Assert.IsFalse(t.Search("matches"));
}
public static void Run()
{
Trie trie = new Trie();
trie.Insert("somestring");
Console.WriteLine(trie.Search("key"));
trie.Insert("key1");
Console.WriteLine(trie.Search("key"));
Console.WriteLine(trie.Search("key1"));
Console.WriteLine(trie.StartsWith("some"));
trie.Insert("abc");
Console.WriteLine(trie.Search("abc"));
Console.WriteLine(trie.Search("ab"));
trie.Insert("ab");
Console.WriteLine(trie.Search("ab"));
trie.Insert("ab");
Console.WriteLine(trie.Search("ab"));
}
public IList<string> FindWords(char[,] board, string[] words)
{
Trie tr = new Trie();
foreach (var w in words)
tr.Insert(w);
List<string> re = new List<string>();
int m = board.GetLength(0);
int n = board.GetLength(1);
bool[,] map = new bool[m, n];
StringBuilder sb = new StringBuilder();
for(int i=0; i< m; i++)
for(int j=0; j< n; j++)
{
Recur(board, tr, i, j, map, m, n, re, "");
}
return re;
}