Spell Checker with Suggestions

You are building a basic spell checker that can suggest corrections for misspelled words. Implement a trie-based structure that can insert words and suggest corrections for a given misspelled word by finding all words that are one character change away. The input is a sequence of commands: 1. 'ADD <word>' - Add a word to the trie. 2. 'SUGGEST <word>' - Suggest words that are one character change away from the given word. The output should be the list of suggestions for each 'SUGGEST' command, sorted in alphabetical order. Example: INPUT: ADD cat ADD cab ADD bat SUGGEST dat SUGGEST cab OUTPUT: bat cab