// practice ground
| # | Title | Topics | Difficulty |
|---|---|---|---|
| 76 | Permutations |
Backtracking
Recursion
|
Medium |
| 77 | Subsets |
Backtracking
Recursion
|
Medium |
| 78 | Combination Sum |
Backtracking
Recursion
|
Medium |
| 79 | Maximum Depth of Binary Tree |
Recursion
Trees
|
Easy |
| 80 | Binary Tree Inorder Traversal |
Recursion
Stacks
Trees
|
Easy |
| 81 | Symmetric Tree |
Recursion
Trees
|
Easy |
| 82 | Diameter of Binary Tree |
Recursion
Trees
|
Medium |
| 83 | Binary Tree Level Order Traversal |
Queues
Trees
|
Medium |
| 84 | Invert Binary Tree |
Recursion
Trees
|
Easy |
| 85 | Validate Binary Search Tree |
Binary Search Tree
Recursion
Trees
|
Medium |
| 86 | Insert into a Binary Search Tree |
Binary Search Tree
Recursion
Trees
|
Medium |
| 87 | Lowest Common Ancestor of a BST |
Binary Search Tree
Recursion
Trees
|
Medium |
| 88 | Jump Game |
Arrays
Dynamic Programming
Greedy
|
Medium |
| 89 | Gas Station |
Arrays
Greedy
|
Medium |
| 90 | Assign Cookies |
Greedy
Sorting
|
Easy |
| 91 | Distance Between Two Points |
Geometry
Math
|
Easy |
| 92 | Area of a Triangle Given Vertices |
Geometry
Math
|
Easy |
| 93 | Fast Exponentiation |
Divide and Conquer
Math
Number Theory
|
Medium |
| 94 | Merge Sort |
Divide and Conquer
Sorting
|
Medium |
| 95 | Implement Trie (Insert and Search) |
Strings
Trie
|
Medium |
| 96 | Count Words With a Given Prefix |
Strings
Trie
|
Medium |
| 97 | Number of Connected Components |
Graphs
Union Find (Disjoint Set)
|
Medium |
| 98 | Redundant Connection |
Graphs
Union Find (Disjoint Set)
|
Medium |
| 99 | Min Stack |
Design
Stacks
|
Medium |
| 100 | Design a Stack With Increment Operation |
Arrays
Design
Stacks
|
Medium |