> For the complete documentation index, see [llms.txt](https://republic-of-cs.gitbook.io/e/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://republic-of-cs.gitbook.io/e/rcs.101/rcs.101.c.md).
# RCS.101.c
{% tabs %}
{% tab title="Map of Contents" %}
***
## Basic Graphs
{% hint style="info" %}
**Trees**
Trees are a common non-linear data structure. They donโt store data in a linear way, but instead organize hierarchically. A tree is normally represented by nodes which contain a value and point to other nodes.
#### Learning Material
* [**Google Tech Dev Guide: Trees**](https://techdevguide.withgoogle.com/paths/data-structures-and-algorithms/#sequence-3)
{% endhint %}
* Learning Material
* [**LeetCode The Hard Way: Graph Theory**](https://leetcodethehardway.com/tutorials/graph-theory/introduction)
* [**LintCode: ็ฌฌไบ็ซ ๏ผๆฐๆฎ็ปๆ๏ผไธ๏ผไนๅนถๆฅ้ไธๅญๅ ธๆ **](https://www.lintcode.com/course/7)
* [**Disjoint Set**](https://leetcode.com/explore/featured/card/graph/618/disjoint-set/3881/)**,** [**CodeForce: UnionFind**](https://codeforces.com/blog/entry/98275)\
(aka **Disjoint Set Union, DSU, UnionFind**)
[**Quick Find**](https://leetcode.com/explore/featured/card/graph/618/disjoint-set/3878/), [**Quick Union**](https://leetcode.com/explore/featured/card/graph/618/disjoint-set/3840/)
* [ ] **E** [**1971. Find if Path Exists in Graph**](https://leetcode.com/problems/find-if-path-exists-in-graph/)
* [ ] **E** [**Number of Islands**](https://www.lintcode.com/problem/433/?showListFe=true\&page=1\&problemTypeId=2\&tagIds=399\&ordering=level\&pageSize=50)
* [**Google Tech Dev Guide: Graphs**](https://techdevguide.withgoogle.com/paths/data-structures-and-algorithms/#sequence-6)
* Practices
* [ ] **M** [**105. Construct Binary Tree from Preorder and Inorder Traversal**](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/)
* [ ] **M** [**178 ยท Graph Valid Tree**](https://www.lintcode.com/problem/178/description)
* [ ] **M** [**128. Longest Consecutive Sequence**](https://leetcode.com/problems/longest-consecutive-sequence/)
* [ ] **M** [**990. Satisfiability of Equality Equations**](https://leetcode.com/problems/satisfiability-of-equality-equations/)
* Graduation Challenge
* [ ] ่ฝ็ญๅบ Undirected graphs, Directed graphs, Weighted graphs, Cyclic graphs, Acyclic Graph ็ๅๅฅ
* [ ] **M** [**1202. Smallest String With Swaps**](https://leetcode.com/problems/smallest-string-with-swaps/)
* [ ] **M** [**547. Number of Provinces**](https://leetcode.com/problems/number-of-provinces/)
* [ ] **M** [**1319. Number of Operations to Make Network Connected**](https://leetcode.com/problems/number-of-operations-to-make-network-connected/)
***
## Heap
{% hint style="info" %}
A heap is a tree-based data structure that usually comes in two varieties: (1) Max-heaps where the the value in any node is greater than all the values in it's child nodes and (2) Min-heaps where the value in any node is less than all of the values in it's child nodes.
#### Learning Material
* [**LeetCode the Hard Way: Heap (Priority Queue)**](https://leetcodethehardway.com/tutorials/basic-topics/heap)
* [ ] **E** [**1046. Last Stone Weight**](https://leetcode.com/problems/last-stone-weight/)
* [ ] **E** [**464 ยท Sort Integers II**](https://www.lintcode.com/problem/464/description) with Heap Sort
* [**Google Tech Dev Guide: Heaps**](https://techdevguide.withgoogle.com/paths/data-structures-and-algorithms/#sequence-5)
{% endhint %}
* Practices
* [ ] **E** [**2974. Minimum Number Game**](https://leetcode.com/problems/minimum-number-game/)
* [ ] **E** [**506. Relative Ranks**](https://leetcode.com/problems/relative-ranks/)
* [ ] **M** [**2336. Smallest Number in Infinite Set**](https://leetcode.com/problems/smallest-number-in-infinite-set/)
* Graduation Challenge
* [ ] **E** [**1464. Maximum Product of Two Elements in an Array**](https://leetcode.com/problems/maximum-product-of-two-elements-in-an-array/)
* [ ] **E** [**1337. The K Weakest Rows in a Matrix**](https://leetcode.com/problems/the-k-weakest-rows-in-a-matrix/)
* [ ] **M** [**451. Sort Characters By Frequency**](https://leetcode.com/problems/sort-characters-by-frequency/)
* [ ] **M** [**1845. Seat Reservation Manager**](https://leetcode.com/problems/seat-reservation-manager/)
