// practice ground
| # | Title | Topics | Difficulty |
|---|---|---|---|
| 301 | Number of Islands II |
Graphs
Union Find (Disjoint Set)
|
Hard |
| 302 | Shortest Path Visiting All Nodes |
Graphs
|
Hard |
| 303 | Alien Dictionary |
Graphs
|
Hard |
| 304 | Reconstruct Itinerary |
Graphs
|
Hard |
| 305 | Sudoku Solver |
Backtracking
Graphs
Matrix
|
Hard |
| 306 | N-Queens II |
Backtracking
Graphs
|
Hard |
| 307 | Network Delay Time |
Graphs
Heaps / Priority Queue
|
Medium |
| 308 | Cheapest Flights Within K Stops |
Dynamic Programming
Graphs
|
Medium |
| 309 | Pacific Atlantic Water Flow |
Graphs
Matrix
|
Medium |
| 310 | Same Tree |
Recursion
Trees
|
Easy |
| 311 | Subtree of Another Tree |
Recursion
Trees
|
Easy |
| 312 | Leaf Similar Trees |
Recursion
Trees
|
Easy |
| 313 | Convert Sorted Array to BST |
Binary Search Tree
Recursion
Trees
|
Easy |
| 314 | Minimum Depth of Binary Tree |
Recursion
Trees
|
Easy |
| 315 | Binary Tree Paths |
Recursion
Trees
|
Easy |
| 316 | Construct Binary Tree from Preorder and Inorder |
Recursion
Trees
|
Medium |
| 317 | Construct Binary Tree from Inorder and Postorder |
Recursion
Trees
|
Medium |
| 318 | Flatten Binary Tree to Linked List |
Recursion
Trees
|
Medium |
| 319 | Populating Next Right Pointers |
Trees
|
Medium |
| 320 | Binary Tree Zigzag Level Order Traversal |
Trees
|
Medium |
| 321 | Count Complete Tree Nodes |
Binary Search
Trees
|
Medium |
| 322 | Find Bottom Left Tree Value |
Trees
|
Medium |
| 323 | Average of Levels in Binary Tree |
Trees
|
Easy |
| 324 | Sum Root to Leaf Numbers |
Recursion
Trees
|
Medium |
| 325 | Maximum Width of Binary Tree |
Trees
|
Medium |
