private void SearchDfs(char[,] board, EngishTrieNodeSimple node, List <string> result, int row, int col, bool[,] used)
{
//如果当前node的word不为空，说明board里走的路径形成的单词，在字典树里找到了，要加入结果集
//不过可能2条路径形成的单词一样，所以要把单词设定成空（其实感觉判断结果集是否包含单词逻辑是一样的，而且不用写个新的EngishTrieNodeSimple，但是words数量多的时候，性能应该不如给字典树加word属性
//找到单词还是要继续循环，就好比字典有ab还有abc和abd，必须等到node的children里找不到当前字符才结束
if (node.Word != null)
{
result.Add(node.Word);
node.MakeNull();
}
EngishTrieNodeSimple curr;
used[row, col] = true;
//向右走
if (row < board.GetLength(0) - 1 && used[row + 1, col] == false && node.TryGet(board[row + 1, col], out curr))
{
SearchDfs(board, curr, result, row + 1, col, used);
}
//向左走
if (row > 0 && used[row - 1, col] == false && node.TryGet(board[row - 1, col], out curr))
{
SearchDfs(board, curr, result, row - 1, col, used);
}
//向下走
if (col < board.GetLength(1) - 1 && used[row, col + 1] == false && node.TryGet(board[row, col + 1], out curr))
{
SearchDfs(board, curr, result, row, col + 1, used);
}
//向上走
if (col > 0 && used[row, col - 1] == false && node.TryGet(board[row, col - 1], out curr))
{
SearchDfs(board, curr, result, row, col - 1, used);
}
used[row, col] = false;
}
public WordSearch2()
{
Root = new EngishTrieNodeSimple();
}
