| Problem | Difficulty |
|---|---|
| 733. Flood Fill | Easy |
| 463. Island Perimeter | Easy |
| 417. Pacific Atlantic Water Flow | Medium |
| 1905. Count Sub Islands | Medium |
| **1559. Detect Cycles in 2D Grid | Medium (1837) |
| Problem | Difficulty | Notes |
|---|---|---|
| 841. Keys and Rooms | Medium (1412) | |
| 1306. Jump Game III | Medium (1396) | |
| **133. Clone Graph | Medium | |
| 399. Evaluate Division | Medium | |
| **2192. All Ancestors of a Node in a Directed Acyclic Graph | Medium (1787) | Very tricky way to build topological sort. |
| 2101. Detonate the Maximum Bombs | Medium (1880) | |
| **721. Accounts Merge | Medium | |
| 2092. Find All People With Secret | Medium (2003) |
- https://leetcode.com/problems/number-of-provinces/description/
- Solved, https://leetcode.com/problems/maximum-number-of-fish-in-a-grid/description/ 1489
- Solved, https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/description/ 1512
- Solved, https://leetcode.com/problems/restore-the-array-from-adjacent-pairs/description/
- https://leetcode.com/problems/number-of-enclaves/submissions/ 1615
- https://leetcode.com/problems/maximum-number-of-moves-in-a-grid/description/ 1625
- https://leetcode.com/problems/remove-methods-from-project/description/ 1710
- https://leetcode.com/problems/count-the-number-of-complete-components/description/ 1769
- https://leetcode.com/problems/maximize-amount-after-two-days-of-conversions/description/ 1787
| Problem | Difficulty |
|---|---|
| 1376. Time Needed to Inform All Employees | Medium (1560) |
| 1443. Minimum Time to Collect All Apples in a Tree | Medium (1682) |
| 1519. Number of Nodes in the Sub-Tree With the Same Label | Medium (1809) |
| **2477. Minimum Fuel Cost to Report to the Capital | Medium (2011) |
| Problem | Difficulty |
|---|---|
| 200. Number of Islands | Medium |
| **130. Surrounded Regions | Medium |
| 1254. Number of Closed Islands | Medium (1659) |
| 2316. Count Unreachable Pairs of Nodes in an Undirected Graph | Medium (1604) |
| 1319. Number of Operations to Make Network Connected | Medium (1633) |
| Problem | Difficulty | Notes |
|---|---|---|
| 695. Max Area of Island | Medium | |
| **827. Making A Large Island | Hard (1934) | How to record the area of the island? How to connect the islands? |
| Problem | Difficulty | Notes |
|---|---|---|
| 1971. Find if Path Exists in Graph | Easy | |
| 797. All Paths From Source to Target | Medium (1383) | |
| **79. Word Search | Medium | Path finding, need backtracking. |
| 980. Unique Paths III | Hard |
| Problem | Difficulty |
|---|---|
| 785. Is Graph Bipartite? | Medium |
| 886. Possible Bipartition | Medium |
| 1042. Flower Planting With No Adjacent | Medium (1712) |
| Problem | Difficulty |
|---|---|
| 207. Course Schedule | Medium |
| **210. Course Schedule II | Medium |
| 2115. Find All Possible Recipes from Given Supplies | Medium (1679) |
| 2192. All Ancestors of a Node in a Directed Acyclic Graph | Medium (1787) |
| 310. Minimum Height Trees | Medium |
- https://leetcode.com/problems/course-schedule-iv/description/ 1692
- https://leetcode.com/problems/loud-and-rich/description/ 1783
- https://leetcode.com/problems/find-eventual-safe-states/description/ 1962
- https://leetcode.com/problems/build-a-matrix-with-conditions/description/ 1960
- https://leetcode.com/problems/parallel-courses-iii/ 2084
| Problem | Difficulty |
|---|---|
| **547. Number of Provinces | Medium |
| 684. Redundant Connection | Medium |
| 721. Accounts Merge | Medium |
| 2316. Count Unreachable Pairs of Nodes in an Undirected Graph | Medium (1604) |
TODO: 七、并查集
TODO: Add explanation videos