1. Anagram Combination Counting Problem Given a list of words and sentences, determine how many unique sentences can be formed by replacing each word with any of its anagrams. Example: words = [‘listen’, ‘silent’, ‘it’, ‘is’] sentences = [‘listen it is silent’, ‘listen it is silent listen’] output = [4, 8] ⸻ 2. Implementing a File-System “find” Command Imagine implementing something like the Unix find command in a high-level language. Write code that can handle queries such as: • Find all files over 5 MB under a directory • Find all XML files under a directory • Advanced: files whose extension is Java OR all XML files with size between 5MB and 10MB ⸻ 3. Currency Conversion Problem Given a log of currency conversion rates (e.g., USD→EUR, EUR→GBP), write a function that converts between any two currencies. Example entries: {“from”:“USD”, “to”:“EUR”, “rate”:1.1} {“from”:“EUR”, “to”:“GBP”, “rate”:1.2} Meaning 1 USD = 1.32 GBP. 4: system design: book store review api