During July 2025, this developer contributed to the DaleStudy/leetcode-study repository by implementing practical solutions for two foundational LeetCode problems: Contains Duplicate and Two Sum. Using TypeScript, they applied a sort-and-scan approach to efficiently detect duplicates and a nested-loop method to identify valid pairs, focusing on clarity and maintainability. Their work emphasized algorithm implementation and problem-solving skills, producing clean, well-documented code that reinforces essential patterns for learners. While the scope was limited to one feature and no bug fixes, the solutions provided concrete, testable examples that enhance the repository’s educational value and support future extension or adaptation by others.