- Tree and Graph: Lowest Common Ancestor (LCA); Disjoint-Set

- String: Prefix Tree (Trie); Suffix Tree

[0042.trapping-rain-water](./problems/42.trapping-rain-water.md):

- [0001.TwoSum](./problems/1.TwoSum.md)🆕

- [0020.Valid Parentheses](./problems/20.validParentheses.md)

- [0501.find-mode-in-binary-search-tree](./problems/501.Find-Mode-in-Binary-Search-Tree.md) 🆕

- [0575.distribute-candies](./problems/575.distribute-candies.md)

- [0002. Add Two Numbers](./problems/2.addTwoNumbers.md)

- [0003. Longest Substring Without Repeating Characters](./problems/3.longestSubstringWithoutRepeatingCharacters.md)

- [1031.maximum-sum-of-two-non-overlapping-subarrays](./problems/1031.maximum-sum-of-two-non-overlapping-subarrays.md)

- [1218.longest-arithmetic-subsequence-of-given-difference.md](./problems/1218.longest-arithmetic-subsequence-of-given-difference.md) 🆕

- [0004.median-of-two-sorted-array](./problems/4.median-of-two-sorted-array.md) 🆕

- [0023.merge-k-sorted-lists](./problems/23.merge-k-sorted-lists.md)

- [0460.lfu-cache](./problems/460.lfu-cache.md) 🆕

- [1168.optimize-water-distribution-in-a-village](./problems/1168.optimize-water-distribution-in-a-village-en.md) 🆕

- [Data Structure](./thinkings/basic-data-structure-en.md) (Drafts)

- [Basic Algorithm](./thinkings/basic-algorithm-en.md)Drafts

- If you have any ideas, [Issues](https://github.com/azl397985856/leetcode/issues) or chat in groups.

- If you want to edit images resources in this project, [here](./assets/drawio/) lists the files that can be edited on [draw.io](https://www.draw.io/).