Word dictionary with wildcards

Design a word dictionary supporting add and wildcard search. Process operations: ["add", word] inserts a lowercase word; ["search", pattern] returns whether any added word matches the pattern, where '.' in the pattern matches any single character (all other characters match literally). The pattern length always equals a stored word's length to match. Return the list of boolean results for the search operations in order. Build a trie and DFS over branches when you hit a '.'.