Array
1. Two Sum
4. Median of Two Sorted Arrays
11. Container With Most Water
15. 3Sum
16. 3Sum Closest
26. Remove Duplicates from Sorted Array
27. Remove Element
31. Next Permutation
33. Search in Rotated Sorted Array
34. Find First and Last Position of Element in Sorted Array
35. Search Insert Position
36. Valid Sudoku
37. Sudoku Solver
39. Combination Sum
40. Combination Sum II
41. First Missing Positive
42. Trapping Rain Water
45. Jump Game II
46. Permutations
47. Permutations II
48. Rotate Image
51. N-Queens
53. Maximum Subarray
54. Spiral Matrix
55. Jump Game
56. Merge Intervals
57. Insert Interval
59. Spiral Matrix II
63. Unique Paths II
64. Minimum Path Sum
66. Plus One
73. Set Matrix Zeroes
74. Search a 2D Matrix
75. Sort Colors
77. Combinations
78. Subsets
79. Word Search
80. Remove Duplicates from Sorted Array II
81. Search in Rotated Sorted Array II
84. Largest Rectangle in Histogram
88. Merge Sorted Array
90. Subsets II
105. Construct Binary Tree from Preorder and Inorder Traversal
106. Construct Binary Tree from Inorder and Postorder Traversal
108. Convert Sorted Array to Binary Search Tree
118. Pascal’s Triangle
119. Pascal’s Triangle II
120. Triangle
121. Best Time to Buy and Sell Stock
122. Best Time to Buy and Sell Stock II
128. Longest Consecutive Sequence
130. Surrounded Regions
135. Candy
136. Single Number
137. Single Number II
150. Evaluate Reverse Polish Notation
152. Maximum Product Subarray
153. Find Minimum in Rotated Sorted Array
154. Find Minimum in Rotated Sorted Array II
162. Find Peak Element
164. Maximum Gap
164. Maximum Gap
167. Two Sum II - Input array is sorted
169. Majority Element
174. Dungeon Game
189. Rotate Array
198. House Robber
200. Number of Islands
204. Count Primes
209. Minimum Size Subarray Sum
212. Word Search II
213. House Robber II
215. Kth Largest Element in an Array
216. Combination Sum III
217. Contains Duplicate
218. The Skyline Problem
219. Contains Duplicate II
220. Contains Duplicate III
228. Summary Ranges
229. Majority Element II
239. Sliding Window Maximum
240. Search a 2D Matrix II
260. Single Number III
268. Missing Number
274. H-Index
275. H-Index II
283. Move Zeroes
284. Peeking Iterator
287. Find the Duplicate Number
300. Longest Increasing Subsequence
303. Range Sum Query - Immutable
498. Diagonal Traverse
500. Keyboard Row
String
3. Longest Substring Without Repeating Characters
5. Longest Palindromic Substring
6. ZigZag Conversion
8. String to Integer (atoi)
12. Integer to Roman
13. Roman to Integer
14. Longest Common Prefix
17. Letter Combinations of a Phone Number
20. Valid Parentheses
22. Generate Parentheses
28. Implement strStr()
30. Substring with Concatenation of All Words
32. Longest Valid Parentheses
43. Multiply Strings
49. Group Anagrams
58. Length of Last Word
65. Valid Number
67. Add Binary
71. Simplify Path
76. Minimum Window Substring
91. Decode Ways
93. Restore IP Addresses
97. Interleaving String
Two Pointers
Database
175. Combine Two Tables
176. Second Highest Salary
177. Nth Highest Salary
178. Rank Scores
180. Consecutive Numbers
181. Employees Earning More Than Their Managers
182. Duplicate Emails
183. Customers Who Never Order
184. Department Highest Salary
185. Department Top Three Salaries
196. Delete Duplicate Emails
197. Rising Temperature
262. Trips and Users
511. Game Play Analysis I
512. Game Play Analysis II
534. Game Play Analysis III
550. Game Play Analysis IV
569. Median Employee Salary
570. Managers with at Least 5 Direct Reports
571. Find Median Given Frequency of Numbers
574. Winning Candidate
577. Employee Bonus
578. Get Highest Answer Rate Question
579. Find Cumulative Salary of an Employee
580. Count Student Number in Departments
584. Find Customer Referee
585. Investments in 2016
586. Customer Placing the Largest Number of Orders
595. Big Countries
596. Classes More Than 5 Students
597. Friend Requests I: Overall Acceptance Rate
601. Human Traffic of Stadium
602. Friend Requests II: Who Has the Most Friends
603. Consecutive Available Seats
607. Sales Person
608. Tree Node
610. Triangle Judgement
612. Shortest Distance in a Plane
613. Shortest Distance in a Line
614. Second Degree Follower
615. Average Salary: Departments VS Company
618. Students Report By Geography
619. Biggest Single Number
620. Not Boring Movies
626. Exchange Seats
627. Swap Salary
1045. Customers Who Bought All Products
1050. Actors and Directors Who Cooperated At Least Three Times
1068. Product Sales Analysis I
1069. Product Sales Analysis II
1070. Product Sales Analysis III
1075. Project Employees I
1076. Project Employees II
1077. Project Employees III
1082. Sales Analysis I
1083. Sales Analysis II
1084. Sales Analysis III
1097. Game Play Analysis V
1098. Unpopular Books
1107. New Users Daily Count
1141. User Activity for the Past 30 Days I
1148. Article Views I
1158. Market Analysis I
1179. Reformat Department Table
1393. Capital Gain/Loss
1407. Top Travellers
1484. Group Sold Products By The Date
1527. Patients With a Condition
1581. Customer Who Visited but Did Not Make Any Transactions
1587. Bank Account Summary II
1667. Fix Names in a Table
1693. Daily Leads and Partners
1729. Find Followers Count
1741. Find Total Time Spent by Each Employee
1757. Recyclable and Low Fat Products
1795. Rearrange Products Table
1873. Calculate Special Bonus
1890. The Latest Login in 2020
1965. Employees With Missing Information