Worked on enhancing the documentation for the doocs/leetcode repository by delivering a detailed explanation of the solution to LeetCode 0974 Subarray Sums Divisible by K. Focused on clarifying the use of hash tables and prefix sums in the algorithm, the documentation outlined the key insight that subarrays are divisible by k when their prefix sums modulo k are equal. The update included step-by-step guidance, addressed edge cases such as negative prefix sums, and improved overall clarity for onboarding developers. Utilized Markdown for technical writing, emphasizing algorithmic thinking, data structures, and clear communication to support maintainability and knowledge sharing.