private void dfs(char[][] board, int x, int y, Trie root, List<String> result) {
char c = board[x][y];
if (c == '#' || root.children[c - 'a'] == null) {
return;
}
root = root.children[c - 'a'];
if (root.word != null) {
result.add(root.word);
root.word = null;
}
board[x][y] = '#';
if (x > 0) {
dfs(board, x - 1, y, root, result);
}
if (x < board.length - 1) {
dfs(board, x + 1, y, root, result);
}
if (y > 0) {
dfs(board, x, y - 1, root, result);
}
if (y < board[0].length - 1) {
dfs(board, x, y + 1, root, result);
}
board[x][y] = c;
}
private void addToTrie(Trie root, String word) {
for (char c : word.toCharArray()) {
int index = c - 'a';
if (root.children[index] == null) {
root.children[index] = new Trie();
}
root = root.children[index];
}
root.word = word;
}
