public void search(
boolean[][] used,
char[][] board,
StringBuilder word,
int i,
int j,
Trie trie,
Set<String> wordsList) {
if (trie.search(word.toString())) {
wordsList.add(word.toString());
return;
}
if (trie.startsWith(word.toString())) {
if (i > 0 && !used[i - 1][j]) {
used[i - 1][j] = true;
word.append(board[i - 1][j]);
search(used, board, word, i - 1, j, trie, wordsList);
word.deleteCharAt(word.length() - 1);
}
if (i < board.length - 1 && !used[i + 1][j]) {
used[i + 1][j] = true;
word.append(board[i + 1][j]);
search(used, board, word, i + 1, j, trie, wordsList);
word.deleteCharAt(word.length() - 1);
}
if (j > 0 && !used[i][j - 1]) {
used[i][j - 1] = true;
word.append(board[i][j - 1]);
search(used, board, word, i, j - 1, trie, wordsList);
word.deleteCharAt(word.length() - 1);
}
if (j < board[0].length - 1 && !used[i][j + 1]) {
used[i][j + 1] = true;
word.append(board[i][j + 1]);
search(used, board, word, i, j + 1, trie, wordsList);
word.deleteCharAt(word.length() - 1);
}
}
}
public void dfs(char[][] board, boolean[][] visited, String str, int i, int j, Trie trie) {
int m = board.length;
int n = board[0].length;
if (i >= m || j >= n || i < 0 || j < 0) return;
if (visited[i][j]) return;
str = str + board[i][j];
// System.out.println(str);
if (!trie.startsWith(str)) return;
if (trie.search(str)) {
result.add(str);
}
visited[i][j] = true;
dfs(board, visited, str, i - 1, j, trie);
dfs(board, visited, str, i + 1, j, trie);
dfs(board, visited, str, i, j - 1, trie);
dfs(board, visited, str, i, j + 1, trie);
visited[i][j] = false;
}
