Find Words That Are Substrings of Other Words

Given an array of strings words (may contain duplicates), return all words that are a substring of another word in the array. Return the list of matching words (order does not matter). This version requires deduplication in the output. Requirements: Provide a baseline approach and analyze its time and space complexity. Propose an optimized approach, give its expected time/space complexity, and implement it. Constraints: 1 <= len(words) <= 2 * 10^4 1 <= len(words[i]) <= 10^3 lowercase English letters only Example: Input: ["category", "cat"] Output: ["cat"] Provide at least 5 test cases including duplicates, identical strings, and a no-match case. Example Input words=["category","cat"] Output ["cat"]