- 1. Two Sum
- 7. Reverse Integer
- 14. Longest Common Prefix
- 20. Valid Parentheses
- 21. Merge Two Sorted Lists
- 26. Remove Duplicates from Sorted Array
- 53. Maximum Subarray
- 69. Sqrt(x)
- 70. Climbing Stairs
- 83. Remove Duplicates from Sorted List
- 88. Merge Sorted Array
- 101. Symmetric Tree
- 104. Maximum Depth of Binary Tree
- 107. Binary Tree Level Order Traversal II
- 108. Convert Sorted Array to Binary Search Tree
- 110. Balanced Binary Tree
- 111. Minimum Depth of Binary Tree
- 112. Path Sum
- 118. Pascal's Triangle
- 119. Pascal's Triangle II
- 121. Best Time to Buy and Sell Stock
- 125. Valid Palindrome
- 136. Single Number
- 141. Linked List Cycle
- 155. Min Stack
- 160. Intersection of Two Linked Lists
- 167. Two Sum II - Input array is sorted
- 170. Two Sum III - Data structure design
- 171. Excel Sheet Column Number
- 198. House Robber
- 202. Happy Number
- 203. Remove Linked List Elements
- 205. Isomorphic Strings
- 206. Reverse Linked List
- 219. Contains Duplicate II
- 226. Invert Binary Tree
- 234. Palindrome Linked List
- 235. Lowest Common Ancestor of a Binary Search Tree
- 242. Valid Anagram
- 246. Strobogrammatic Number
- 252. Meeting Rooms
- 256. Paint House
- 257. Binary Tree Paths
- 266. Palindrome Permutation
- 268. Missing Number
- 270. Closest Binary Search Tree Value
- 278. First Bad Version
- 283. Move Zeroes
- 344. Reverse String
- 345. Reverse Vowels of a String
- 346. Moving Average from Data Stream
- 349. Intersection of Two Arrays
- 350. Intersection of Two Arrays II
- 359. Logger Rate Limiter
- 387. First Unique Character in a String
- 389. Find the Difference
- 404. Sum of Left Leaves
- 412. Fizz Buzz
- 437. Path Sum III
- 448. Find All Numbers Disappeared in an Array
- 463. Island Perimeter
- 509. Fibonacci Number
- 543. Diameter of Binary Tree
- 572. Subtree of Another Tree
- 599. Minimum Index Sum of Two Lists
- 617. Merge Two Binary Trees
- 652. Find Duplicate Subtrees
- 671. Second Minimum Node In a Binary Tree
- 686. Repeated String Match
- 687. Longest Univalue Path
- 700. Search in a Binary Search Tree
- 705. Design HashSet
- 716. Max Stack
- 746. Min Cost Climbing Stairs
- 771. Jewels and Stones
- 819. Most Common Word
- 844. Backspace String Compare
- 876. Middle of the Linked List
- 905. Sort Array By Parity
- 938. Range Sum of BST
- 941. Valid Mountain Array
- 965. Univalued Binary Tree
- 1047. Remove All Adjacent Duplicates In String
- 1056. Confusing Number
- 1086. High Five
- 1089. Duplicate Zeros
- 1207. Unique Number of Occurrences
- 1281. Subtract the Product and Sum of Digits of an Integer
- 1290. Convert Binary Number in a Linked List to Integer
- 1295. Find Numbers with Even Number of Digits
- 1299. Replace Elements with Greatest Element on Right Side
- 1304. Find N Unique Integers Sum up to Zero
- 1309. Decrypt String from Alphabet to Integer Mapping
- 1317. Convert Integer to the Sum of Two No-Zero Integers
- 1323. Maximum 69 Number
- 1331. Rank Transform of an Array
- 1342. Number of Steps to Reduce a Number to Zero
- 1356. Sort Integers by The Number of 1 Bits
- 5143. Decompress Run-Length Encoded List
- 2. Add Two Numbers
- 3. Longest Substring Without Repeating Characters
- 11. Container With Most Water
- 19. Remove Nth Node From End of List
- 22. Generate Parentheses
- 24. Swap Nodes in Pairs
- 36. Valid Sudoku
- 46. Permutations
- 49. Group Anagrams
- 50. Pow(x, n)
- 56. Merge Intervals
- 61. Rotate List
- 82. Remove Duplicates from Sorted List II
- 94. Binary Tree Inorder Traversal
- 96. Unique Binary Search Trees
- 98. Validate Binary Search Tree
- 102. Binary Tree Level Order Traversal
- 105. Construct Binary Tree from Preorder and Inorder Traversal
- 106. Construct Binary Tree from Inorder and Postorder Traversal
- 129. Sum Root to Leaf Numbers
- 138. Copy List with Random Pointer
- 142. Linked List Cycle II
- 144. Binary Tree Preorder Traversal
- 146. LRU Cache
- 150. Evaluate Reverse Polish Notation
- 159. Longest Substring with At Most Two Distinct Characters
- 173. Binary Search Tree Iterator
- 200. Number of Islands
- 279. Perfect Squares
- 280. Wiggle Sort
- 286. Walls and Gates
- 230. Kth Smallest Element in a BST
- 236. Lowest Common Ancestor of a Binary Tree
- 238. Product of Array Except Self
- 249. Group Shifted Strings
- 250. Count Univalue Subtrees
- 253. Meeting Rooms II
- 288. Unique Word Abbreviation
- 328. Odd Even Linked List
- 379. Design Phone Directory
- 380. Insert Delete GetRandom O(1)
- 394. Decode String
- 430. Flatten a Multilevel Doubly Linked List
- 454. 4Sum II
- 536. Construct Binary Tree from String
- 622. Design Circular Queue
- 692. Top K Frequent Words
- 701. Insert into a Binary Search Tree
- 707. Design Linked List
- 708. Insert into a Sorted Circular Linked List
- 731. My Calendar II
- 739. Daily Temperatures
- 841. Keys and Rooms
- 904. Fruit Into Baskets
- 939. Minimum Area Rectangle
- 1007. Minimum Domino Rotations For Equal Row
- 1008. Construct Binary Search Tree from Preorder Traversal
- 1055. Shortest Way to Form String
- 1146. Snapshot Array
- 1161. Maximum Level Sum of a Binary Tree
- 1249. Minimum Remove to Make Valid Parentheses
- 1302. Deepest Leaves Sum
- 1305. All Elements in Two Binary Search Trees
- 1306. Jump Game III
- 1310. XOR Queries of a Subarray
- 1324. Print Words Vertically
- 1325. Delete Leaves With a Given Value
- 1328. Break a Palindrome
- 1343. Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold
- 1344. Angle Between Hands of a Clock
- 1357. Apply Discount Every n Orders
- 5145. Sum of Nodes with Even-Valued Grandparent