- 191. Number of 1 Bits
- 20. Valid Parentheses
- 278. First Bad Version
- 125. Valid Palindrome
- 141. Linked List Cycle
- 110. Balanced Binary Tree
- 1. Two Sum
- 234. Palindrome Linked List
- 121. Best Time to Buy and Sell Stock
- 409. Longest Palindrome
- 704. Binary Search
- 383. Ransom Note
- 100. Same Tree
- 217. Contains Duplicate
- 242. Valid Anagram
- 169. Majority Element
- 104. Maximum Depth of Binary Tree
- 206. Reverse Linked List
- 226. Invert Binary Tree
- 876. Middle of the Linked List
- 219. Contains Duplicate II
- 643. Maximum Average Subarray I
- 54. Spiral Matrix
- 316. Remove Duplicate Letters
- 53. Maximum Subarray
- 235. Lowest Common Ancestor of a Binary Search Tree
- 238. Product of Array Except Self
- 739. Daily Temperatures
- 77. Combinations
- 22. Generate Parentheses
- 78. Subsets
- 973. K Closest Points to Origin
- 3. Longest Substring Without Repeating Characters
- 102. Binary Tree Level Order Traversal(*)
- 150. Evaluate Reverse Polish Notation
- 209. Minimum Size Subarray Sum(*)
- 187. Repeated DNA Sequences
- 424. Longest Repeating Character Replacement(*)