DaleStudy/leetcode-study
Apr 2025 – Aug 2025
5 Months active
Languages Used
Java
Technical Skills
AlgorithmAlgorithm ImplementationArray ManipulationBacktrackingBinary SearchCode Formatting
sora0319
PROFILE
Sora0319
Over five months, Sojeoung Jeong developed a comprehensive algorithm library in the DaleStudy/leetcode-study repository, focusing on reusable solutions for arrays, strings, trees, graphs, and scheduling problems. Leveraging Java and advanced data structures such as tries, binary search trees, and linked lists, Sojeoung implemented dynamic programming, greedy, and backtracking techniques to address a wide range of coding challenges. The work included optimizing memory usage, improving code formatting, and ensuring output consistency, which enhanced maintainability and onboarding. By fixing critical bugs and expanding coverage to real-world scenarios like meeting scheduling, Sojeoung delivered a robust, interview-ready resource for algorithmic problem solving.
Overall Statistics
Feature vs Bugs
91%Features
Repository Contributions
100Total
Bugs
5
Commits
100
Features
53
Lines of code
2,138
Activity Months5
Your Network
251 people
Work History
August 2025
18 Commits • 2 Features
Aug 1, 2025August 2025 monthly summary for DaleStudy/leetcode-study. Delivered key feature improvements, fixed critical bug in rotated sorted arrays, and enhanced code quality. Result: reduced memory usage for climbing stairs, robust word-break DP implementation, corrected minimum-element detection, and extensive codebase cleanup to improve readability and maintainability. These efforts deliver measurable business value through more efficient solutions, increased reliability, and a stronger foundation for future problem solving.
18 Commits • 2 Features
Aug 1, 2025August 2025 monthly summary for DaleStudy/leetcode-study. Delivered key feature improvements, fixed critical bug in rotated sorted arrays, and enhanced code quality. Result: reduced memory usage for climbing stairs, robust word-break DP implementation, corrected minimum-element detection, and extensive codebase cleanup to improve readability and maintainability. These efforts deliver measurable business value through more efficient solutions, increased reliability, and a stronger foundation for future problem solving.
August 2025
July 2025
10 Commits • 8 Features
Jul 1, 2025July 2025 performance summary for DaleStudy/leetcode-study. Delivered a suite of algorithmic solutions focused on DP, BFS, hashing, and performance optimizations, expanding problem-solving coverage and reusable patterns.
July 2025
10 Commits • 8 Features
Jul 1, 2025July 2025 performance summary for DaleStudy/leetcode-study. Delivered a suite of algorithmic solutions focused on DP, BFS, hashing, and performance optimizations, expanding problem-solving coverage and reusable patterns.
June 2025
22 Commits • 12 Features
Jun 1, 2025June 2025 monthly summary for DaleStudy/leetcode-study: Delivered extensive improvements across data structures, problem domains, and code quality, building a reusable, interview-ready algorithm library and practical scheduling utilities. The work expanded coverage to binary trees, graphs, linked lists, arrays/DP, intervals, BSTs, and data streams, with serialization support and scheduling capabilities.
22 Commits • 12 Features
Jun 1, 2025June 2025 monthly summary for DaleStudy/leetcode-study: Delivered extensive improvements across data structures, problem domains, and code quality, building a reusable, interview-ready algorithm library and practical scheduling utilities. The work expanded coverage to binary trees, graphs, linked lists, arrays/DP, intervals, BSTs, and data streams, with serialization support and scheduling capabilities.
June 2025
May 2025
25 Commits • 10 Features
May 1, 2025Month: 2025-05 | Repository: DaleStudy/leetcode-study. Delivered a broad expansion of the problem-solving library, focusing on reusable data structures, comprehensive string processing utilities, and wide-ranging algorithmic solutions. Emphasis on correctness, performance, and maintainable design to support interview prep and performance reviews. No dedicated bug fixes recorded in the provided data; improvements centered on feature completeness, edge-case handling, and code quality. Key features delivered: - Trie Prefix Tree and Word Search Design: implemented trie/prefix tree data structure with Add/Search Words capability. Commits: a4041779e353038fea1acc4c2c2bd87a1a7cda7c; 3ee984650f70e09be70cf5f39b4887a3fbb45acf - String Processing and Encoding suite: encoding/decoding, group anagrams, word break, longest substring without repeating characters, and valid parentheses. Commits: 133cd807107a1cf89d64e4a9b920cbace6be2d0c; 01df82301b12b691a0e7e81802e261f859bb83cc; 51813d3a1ae4a0210755fe48f806eebf65fb87ff; 7230f42ce4c0b8011f16fe62de348d3d184b7476; be74398cefd8bc5919274fd56497305e1d9941a5 - Array/DP and Greedy Problems: stock buy/sell, container with most water, LIS, and unique paths. Commits: 3af456c64aa4c034ba0dddb994c856ee46fa526e; a91fa7926386aea790eb42f98ae46920b138ff0a; 4cbf92fce2e091758607d82c251377b619f4c916; ab5451ba4626ed920309657a1adb49081028beb2 - Matrix/Grid Problems: spiral matrix, set matrix zeros, number of islands. Commits: a98baee9bbc4af2f42523f324cdbc3d1daf790f8; 05ef73ec3f7fa02a40769262019c5aa8139ea39a; 86c96c33f468820343779a38943d1bdc204daa66 - Graph Theory, Linked Lists & Data Structures: clone graph, Pacific Atlantic water flow, reverse linked list, and cycle detection. Commits: 2dac4f4065d274bb5e14762b30eaea942ee098d9; d0416401b9eb5606ff7575f793d6147403fe923f; 3ca58716fe355cd5b12c77b2e5736132166a087c; bde4810250ec554ae6cfe7620b5272707476119b - Dynamic Programming, Substrings & Subsequences: LCS, longest repeating character replacement, palindromic substrings, minimum window substring, maximum product subarray. Commits: 70b7a4ab0fe3b8b38a006fb7db7a57d6c39a8c60; 706f91020815537b46758be48606c5979bfb7be5; fc2ad732f99ac2b56b600d999e2855f126cdec4a; 0eefdee11c324d46e19d3d7a05c6a61dbac85568; ea463a445751f9575611b45cbcba0c517b7d0d1c - Linked List & Data Structures improvements: reverse linked list and cycle detection. Commits: 3ca58716fe355cd5b12c77b2e5736132166a087c; bde4810250ec554ae6cfe7620b5272707476119b - Bit Manipulation: reverse bits. Commit: e131cf7a8fd7ff977c90d9a30c44696782df7771 - Arrays & Hashing: sum of two integers (Two Sum). Commit: 18a30cca1354fa2af0666fd8727065929d7c16aa Overall impact: - Significantly expanded problem coverage and modular design, enabling faster practice, easier onboarding for new contributors, and a stronger foundation for interview prep. - Improved code quality and maintainability through consistent naming, structured commits, and clear problem-oriented modules. - Enhanced problem-solving breadth across data structures, graph theory, DP, and string processing, supporting both learning and demonstration scenarios. Technologies/skills demonstrated: - Data structures: Trie, linked lists, graphs, sets/maps, matrices - Algorithms: DP, greedy, backtracking patterns implicitly via problem types, graph traversal and cloning - Problem-solving breadth: 15+ problem domains across arrays, strings, matrices, graphs, and data structures - Code quality: modular design, commit discipline, edge-case thinking, and readability Note: If you would like, I can break this into a slide-ready deck or a one-page performance review with metric-style bullets (e.g., problem-domain coverage, average commits per feature, test coverage scores).
May 2025
25 Commits • 10 Features
May 1, 2025Month: 2025-05 | Repository: DaleStudy/leetcode-study. Delivered a broad expansion of the problem-solving library, focusing on reusable data structures, comprehensive string processing utilities, and wide-ranging algorithmic solutions. Emphasis on correctness, performance, and maintainable design to support interview prep and performance reviews. No dedicated bug fixes recorded in the provided data; improvements centered on feature completeness, edge-case handling, and code quality. Key features delivered: - Trie Prefix Tree and Word Search Design: implemented trie/prefix tree data structure with Add/Search Words capability. Commits: a4041779e353038fea1acc4c2c2bd87a1a7cda7c; 3ee984650f70e09be70cf5f39b4887a3fbb45acf - String Processing and Encoding suite: encoding/decoding, group anagrams, word break, longest substring without repeating characters, and valid parentheses. Commits: 133cd807107a1cf89d64e4a9b920cbace6be2d0c; 01df82301b12b691a0e7e81802e261f859bb83cc; 51813d3a1ae4a0210755fe48f806eebf65fb87ff; 7230f42ce4c0b8011f16fe62de348d3d184b7476; be74398cefd8bc5919274fd56497305e1d9941a5 - Array/DP and Greedy Problems: stock buy/sell, container with most water, LIS, and unique paths. Commits: 3af456c64aa4c034ba0dddb994c856ee46fa526e; a91fa7926386aea790eb42f98ae46920b138ff0a; 4cbf92fce2e091758607d82c251377b619f4c916; ab5451ba4626ed920309657a1adb49081028beb2 - Matrix/Grid Problems: spiral matrix, set matrix zeros, number of islands. Commits: a98baee9bbc4af2f42523f324cdbc3d1daf790f8; 05ef73ec3f7fa02a40769262019c5aa8139ea39a; 86c96c33f468820343779a38943d1bdc204daa66 - Graph Theory, Linked Lists & Data Structures: clone graph, Pacific Atlantic water flow, reverse linked list, and cycle detection. Commits: 2dac4f4065d274bb5e14762b30eaea942ee098d9; d0416401b9eb5606ff7575f793d6147403fe923f; 3ca58716fe355cd5b12c77b2e5736132166a087c; bde4810250ec554ae6cfe7620b5272707476119b - Dynamic Programming, Substrings & Subsequences: LCS, longest repeating character replacement, palindromic substrings, minimum window substring, maximum product subarray. Commits: 70b7a4ab0fe3b8b38a006fb7db7a57d6c39a8c60; 706f91020815537b46758be48606c5979bfb7be5; fc2ad732f99ac2b56b600d999e2855f126cdec4a; 0eefdee11c324d46e19d3d7a05c6a61dbac85568; ea463a445751f9575611b45cbcba0c517b7d0d1c - Linked List & Data Structures improvements: reverse linked list and cycle detection. Commits: 3ca58716fe355cd5b12c77b2e5736132166a087c; bde4810250ec554ae6cfe7620b5272707476119b - Bit Manipulation: reverse bits. Commit: e131cf7a8fd7ff977c90d9a30c44696782df7771 - Arrays & Hashing: sum of two integers (Two Sum). Commit: 18a30cca1354fa2af0666fd8727065929d7c16aa Overall impact: - Significantly expanded problem coverage and modular design, enabling faster practice, easier onboarding for new contributors, and a stronger foundation for interview prep. - Improved code quality and maintainability through consistent naming, structured commits, and clear problem-oriented modules. - Enhanced problem-solving breadth across data structures, graph theory, DP, and string processing, supporting both learning and demonstration scenarios. Technologies/skills demonstrated: - Data structures: Trie, linked lists, graphs, sets/maps, matrices - Algorithms: DP, greedy, backtracking patterns implicitly via problem types, graph traversal and cloning - Problem-solving breadth: 15+ problem domains across arrays, strings, matrices, graphs, and data structures - Code quality: modular design, commit discipline, edge-case thinking, and readability Note: If you would like, I can break this into a slide-ready deck or a one-page performance review with metric-style bullets (e.g., problem-domain coverage, average commits per feature, test coverage scores).
April 2025
25 Commits • 21 Features
Apr 1, 2025April 2025, DaleStudy/leetcode-study: Delivered a broad library of LeetCode solutions and improved output reliability. Implemented 20+ new solutions across arrays, strings, DP, and data structures (e.g., Contains Duplicate, Two Sum, Top K Frequent Elements, Longest Consective Sequence, Product of Array Except Self, Decode Ways, Maximum Subarray Sum, Word Search, Coin Change, Merge Two Sorted Lists, and more). Fixed output formatting to ensure newline across multiple tasks, with three separate commits, and enforced trailing newline consistency to improve maintainability and CI reliability. The work enhances practice throughput, provides a reusable algorithm library, and strengthens code quality for downstream consumers. Key accomplishments include delivering core problem solutions, applying a mix of DP, hashing, sliding window, and binary search techniques, and improving project hygiene and onboarding readiness.
25 Commits • 21 Features
Apr 1, 2025April 2025, DaleStudy/leetcode-study: Delivered a broad library of LeetCode solutions and improved output reliability. Implemented 20+ new solutions across arrays, strings, DP, and data structures (e.g., Contains Duplicate, Two Sum, Top K Frequent Elements, Longest Consective Sequence, Product of Array Except Self, Decode Ways, Maximum Subarray Sum, Word Search, Coin Change, Merge Two Sorted Lists, and more). Fixed output formatting to ensure newline across multiple tasks, with three separate commits, and enforced trailing newline consistency to improve maintainability and CI reliability. The work enhances practice throughput, provides a reusable algorithm library, and strengthens code quality for downstream consumers. Key accomplishments include delivering core problem solutions, applying a mix of DP, hashing, sliding window, and binary search techniques, and improving project hygiene and onboarding readiness.
April 2025
Activity
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Quality Metrics
Correctness89.4%
Maintainability87.2%
Architecture86.6%
Performance84.0%
AI Usage20.6%
Skills & Technologies
Programming Languages
Java
Technical Skills
AlgorithmAlgorithm DesignAlgorithm ImplementationAlgorithmsArray ManipulationBacktrackingBinary SearchBinary Search TreeBinary Search TreesBinary TreesBit ManipulationBreadth-First SearchBreadth-First Search (BFS)Code FormattingData Structures
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline