During November 2025, LJH developed an Array Duplicate Detection Utility for the DaleStudy/leetcode-study repository, focusing on enhancing data integrity and processing efficiency in array operations. Leveraging TypeScript and algorithm development skills, LJH implemented a Set-based approach that detects duplicates in linear time, enabling O(n) performance even on large datasets. The utility was designed for production use and reusability, consolidating duplicate-check logic to improve code quality and maintainability throughout the codebase. While the work was limited to a single feature within the month, it demonstrated a thoughtful application of efficient algorithms and clean TypeScript implementation for practical problem-solving.