/leetcode

Primary LanguageC++

LeetCode

Table of Contents

LeetCode 75

  • 75 Essential & Trending Problems
  • Must-do problem list for interview prep
  • Best for 1~3 month of prep time

Array / String

  1. 1768. Merge Strings Alternately [EASY] (C++)
  2. 1071. Greatest Common Divisor of Strings [EASY] (C++)
  3. 1431. Kids With the Greatest Number of Candies [EASY] (C++)
  4. 605. Can Place Flowers [EASY] (C++)
  5. 345. Reverse Vowels of a String [EASY] (C++)
  6. 151. Reverse Words in a String [MEDIUM] (C++)
  7. 238. Product of Array Except Self [MEDIUM] (C++)
  8. 334. Increasing Triplet Subsequence [MEDIUM] (C++)
  9. 443. String Compression [MEDIUM] (C++)

Two Pointers

  1. 283. Move Zeroes [EASY] (C++)
  2. 392. Is Subsequence [EASY] (C++)
  3. 11. Container With Most Water [MEDIUM] (C++)
  4. 1679. Max Number of K-Sum Pairs [MEDIUM] (C++)

Sliding Window

  1. 643. Maximum Average Subarray I [EASY] (C++)
  2. 1456. Maximum Number of Vowels in a Substring of Given Length [MEDIUM] (C++)
  3. 1004. Max Consecutive Ones III [MEDIUM] (C++)
  4. 1493. Longest Subarray of 1's After Deleting One Element [MEDIUM] (C++)

Prefix Sum

  1. 1732. Find the Highest Altitude [EASY] (C++)
  2. 724. Find Pivot Index [EASY] (C++)

Hash Map / Set

  1. 2215. Find the Difference of Two Arrays [EASY] (C++)
  2. 1207. Unique Number of Occurrences [EASY] (C++)
  3. 1657. Determine if Two Strings Are Close [MEDIUM] (C++)
  4. 2352. Equal Row and Column Pairs [MEDIUM] (C++)

Stack

  1. 2390. Removing Stars From a String [MEDIUM] (C++)
  2. 735. Asteroid Collision [MEDIUM] (C++)
  3. 394. Decode String [MEDIUM] (C++)

Queue

  1. 933. Number of Recent Calls [EASY] (C++)
  2. 649. Dota2 Senate [MEDIUM] (C++)

Linked List

  1. 2095. Delete the Middle Node of a Linked List [MEDIUM] (C++)
  2. 328. Odd Even Linked List [MEDIUM] (C++)
  3. 206. Reverse Linked List [EASY] (C++)
  4. 2130. Maximum Twin Sum of a Linked List [MEDIUM] (C++)

Binary Tree - DFS

  1. 104. Maximum Depth of Binary Tree [EASY] (C++)
  2. 872. Leaf-Similar Trees [EASY] (C++)
  3. 1448. Count Good Nodes in Binary Tree [MEDIUM] (C++)
  4. 437. Path Sum III [MEDIUM] (C++)
  5. 1372. Longest ZigZag Path in a Binary Tree [MEDIUM] (C++)
  6. 236. Lowest Common Ancestor of a Binary Tree [MEDIUM] (C++)

Binary Tree - BFS

  1. 199. Binary Tree Right Side View [MEDIUM] (C++)
  2. 1161. Maximum Level Sum of a Binary Tree [MEDIUM] (C++)

Binary Search Tree

  1. 700. Search in a Binary Search Tree [EASY] (C++)
  2. 450. Delete Node in a BST [MEDIUM] (C++)

Graphs - DFS

  1. 841. Keys and Rooms [MEDIUM] (C++)
  2. 547. Number of Provinces [MEDIUM] (C++)
  3. 1466. Reorder Routes to Make All Paths Lead to the City Zero [MEDIUM] (C++)
  4. 399. Evaluate Division [MEDIUM] (C++)

Graphs - BFS

  1. 1926. Nearest Exit from Entrance in Maze [MEDIUM] (C++)
  2. 994. Rotting Oranges [MEDIUM] (C++)

Heap / Priority Queue

  1. 215. Kth Largest Element in an Array [MEDIUM] (C++)
  2. 2336. Smallest Number in Infinite Set [MEDIUM] (C++)
  3. 2542. Maximum Subsequence Score [MEDIUM] (C++)
  4. 2462. Total Cost to Hire K Workers [MEDIUM] (C++)

Binary Search

  1. 374. Guess Number Higher or Lower [EASY] (C++)
  2. 2300. Successful Pairs of Spells and Potions [MEDIUM] (C++)
  3. 162. Find Peak Element [MEDIUM] (C++)
  4. 875. Koko Eating Bananas [MEDIUM] (C++)

Backtracking

  1. 17. Letter Combinations of a Phone Number [MEDIUM] (C++)
  2. 216. Combination Sum III [MEDIUM] (C++)

DP - 1D

  1. 1137. N-th Tribonacci Number [EASY] (C++)
  2. 746. Min Cost Climbing Stairs [EASY] (C++)
  3. 198. House Robber [MEDIUM] (C++)
  4. 790. Domino and Tromino Tiling [MEDIUM] (C++)

DP - Multidimensional

  1. 62. Unique Paths [MEDIUM] (C++)
  2. 1143. Longest Common Subsequence [MEDIUM] (C++)
  3. 714. Best Time to Buy and Sell Stock with Transaction Fee [MEDIUM] (C++)
  4. 72. Edit Distance [MEDIUM] (C++)

Bit Manipulation

  1. 338. Counting Bits [EASY] (C++)
  2. 136. Single Number [EASY] (C++)
  3. 1318. Minimum Flips to Make a OR b Equal to c [MEDIUM] (C++)

Trie

  1. 208. Implement Trie (Prefix Tree) [MEDIUM] (C++)
  2. 1268. Search Suggestions System [MEDIUM] (C++)

Intervals

  1. 435. Non-overlapping Intervals [MEDIUM] (C++)
  2. 452. Minimum Number of Arrows to Burst Balloons [MEDIUM] (C++)

Monotonic Stack

  1. 739. Daily Temperatures [MEDIUM] (C++)
  2. 901. Online Stock Span [MEDIUM] (C++)

Top Interview 150

  • 150 Original & Classic Questions
  • Covers comprehensive interview topics
  • Best for 3+ months of prep time
  • Problems support high-quality editorials

Array / String

  1. 88. Merge Sorted Array [EASY] (C++)
  2. 27. Remove Element [EASY] (C++)
  3. 26. Remove Duplicates from Sorted Array [EASY] (C++)
  4. 80. Remove Duplicates from Sorted Array II [MEDIUM] (C++)
  5. 169. Majority Element [EASY] (C++)
  6. 189. Rotate Array [MEDIUM] (C++)
  7. 121. Best Time to Buy and Sell Stock [EASY] (C++)
  8. 122. Best Time to Buy and Sell Stock II [MEDIUM] (C++)
  9. 55. Jump Game [MEDIUM] (C++)
  10. 45. Jump Game II [MEDIUM] (C++)
  11. 274. H-Index [MEDIUM] (C++)
  12. 380. Insert Delete GetRandom O(1) [MEDIUM] (C++)
  13. 238. Product of Array Except Self [MEDIUM] (C++)
  14. 134. Gas Station [MEDIUM] (C++)
  15. 135. Candy [HARD] (C++)
  16. 42. Trapping Rain Water [HARD] (C++)
  17. 13. Roman to Integer [EASY] (C++)
  18. 12. Integer to Roman [MEDIUM] (C++)
  19. 58. Length of Last Word [EASY] (C++)
  20. 14. Longest Common Prefix [EASY] (C++)
  21. 151. Reverse Words in a String [MEDIUM] (C++)
  22. 6. Zigzag Conversion [MEDIUM] (C++)
  23. 28. Find the Index of the First Occurrence in a String [EASY] (C++)
  24. 68. Text Justification [HARD] (C++)

Two Pointers

  1. 125. Valid Palindrome [EASY]
  2. 392. Is Subsequence [EASY] (C++)
  3. 167. Two Sum II - Input Array Is Sorted [MEDIUM] (C++)
  4. 11. Container With Most Water [MEDIUM] (C++)
  5. 15. 3Sum [MEDIUM] (C++)

Sliding Window

  1. 209. Minimum Size Subarray Sum [MEDIUM] (C++)
  2. 3. Longest Substring Without Repeating Characters [MEDIUM] (C++)
  3. 30. Substring with Concatenation of All Words [HARD] (C++)
  4. 76. Minimum Window Substring [HARD] (C++)

Matrix

  1. 36. Valid Sudoku [MEDIUM] (C++)
  2. 54. Spiral Matrix [MEDIUM] (C++)
  3. 48. Rotate Image [MEDIUM] (C++)
  4. 73. Set Matrix Zeroes [MEDIUM] (C++)
  5. 289. Game of Life [MEDIUM] (C++)

Hashmap

  1. 383. Ransom Note [EASY] (C++)
  2. 205. Isomorphic Strings [EASY] (C++)
  3. 290. Word Pattern [EASY] (C++)
  4. 242. Valid Anagram [EASY] (C++)
  5. 49. Group Anagrams [MEDIUM] (C++)
  6. 1. Two Sum [EASY] (C++)
  7. 202. Happy Number [EASY] (C++)
  8. 219. Contains Duplicate II [EASY] (C++)
  9. 128. Longest Consecutive Sequence [MEDIUM] (C++)

Intervals

  1. 228. Summary Ranges [EASY] (C++)
  2. 56. Merge Intervals [MEDIUM] (C++)
  3. 57. Insert Interval [MEDIUM] (C++)
  4. 452. Minimum Number of Arrows to Burst Balloons [MEDIUM] (C++)

Stack

  1. 20. Valid Parentheses [EASY] (C++)
  2. 71. Simplify Path [MEDIUM] (C++)
  3. 155. Min Stack [MEDIUM] (C++)
  4. 150. Evaluate Reverse Polish Notation [MEDIUM] (C++)
  5. 224. Basic Calculator [HARD] (C++)

Linked List

  1. 141. Linked List Cycle [EASY] (C++)
  2. 2. Add Two Numbers [MEDIUM] (C++)
  3. 21. Merge Two Sorted Lists [EASY] (C++)
  4. 138. Copy List with Random Pointer [MEDIUM]
  5. 92. Reverse Linked List II [MEDIUM] (C++)
  6. 25. Reverse Nodes in k-Group [HARD] (C++)
  7. 19. Remove Nth Node From End of List [MEDIUM] (C++)
  8. 82. Remove Duplicates from Sorted List II [MEDIUM]
  9. 61. Rotate List [MEDIUM] (C++)
  10. 86. Partition List [MEDIUM]
  11. 146. LRU Cache [MEDIUM] (C++)

Binary Tree General

  1. 104. Maximum Depth of Binary Tree [EASY] (C++)
  2. 100. Same Tree [EASY] (C++)
  3. 226. Invert Binary Tree [EASY] (C++)
  4. 101. Symmetric Tree [EASY] (C++)
  5. 105. Construct Binary Tree from Preorder and Inorder Traversal [MEDIUM] (C++)
  6. 106. Construct Binary Tree from Inorder and Postorder Traversal [MEDIUM] (C++)
  7. 117. Populating Next Right Pointers in Each Node II [MEDIUM] (C++)
  8. 114. Flatten Binary Tree to Linked List [MEDIUM] (C++)
  9. 112. Path Sum [EASY] (C++)
  10. 129. Sum Root to Leaf Numbers [MEDIUM] (C++)
  11. 124. Binary Tree Maximum Path Sum [HARD] (C++)
  12. 173. Binary Search Tree Iterator [MEDIUM] (C++)
  13. 222. Count Complete Tree Nodes [EASY] (C++)
  14. 236. Lowest Common Ancestor of a Binary Tree [MEDIUM] (C++)

Binary Tree BFS

  1. 199. Binary Tree Right Side View [MEDIUM] (C++)
  2. 637. Average of Levels in Binary Tree [EASY] (C++)
  3. 102. Binary Tree Level Order Traversal [MEDIUM] (C++)
  4. 103. Binary Tree Zigzag Level Order Traversal [MEDIUM] (C++)

Binary Search Tree

  1. 530. Minimum Absolute Difference in BST [EASY] (C++)
  2. 230. Kth Smallest Element in a BST [MEDIUM] (C++)
  3. 98. Validate Binary Search Tree [MEDIUM] (C++)

Graph General

  1. 200. Number of Islands [MEDIUM] (C++)
  2. 130. Surrounded Regions [MEDIUM] (C++)
  3. 133. Clone Graph [MEDIUM] (C++)
  4. 399. Evaluate Division [MEDIUM] (C++)
  5. 207. Course Schedule [MEDIUM] (C++)
  6. 210. Course Schedule II [MEDIUM] (C++)

Graph BFS

  1. 909. Snakes and Ladders [MEDIUM] (C++)
  2. 433. Minimum Genetic Mutation [MEDIUM] (C++)
  3. 127. Word Ladder [HARD] (C++)

Trie

  1. 208. Implement Trie (Prefix Tree) [MEDIUM] (C++)
  2. 211. Design Add and Search Words Data Structure [MEDIUM] (C++)
  3. 212. Word Search II [HARD] (C++)

Backtracking

  1. 17. Letter Combinations of a Phone Number [MEDIUM] (C++)
  2. 77. Combinations [MEDIUM] (C++)
  3. 46. Permutations [MEDIUM] (C++)
  4. 39. Combination Sum [MEDIUM] (C++)
  5. 52. N-Queens II [HARD]
  6. 22. Generate Parentheses [MEDIUM] (C++)
  7. 79. Word Search [MEDIUM] (C++)

Divide & Conquer

  1. 108. Convert Sorted Array to Binary Search Tree [EASY] (C++)
  2. 148. Sort List [MEDIUM] (C++)
  3. 427. Construct Quad Tree [MEDIUM] (C++)
  4. 23. Merge k Sorted Lists [HARD] (C++)

Kadane's Algorithm

  1. 53. Maximum Subarray [MEDIUM] (C++)
  2. 918. Maximum Sum Circular Subarray [MEDIUM] (C++)

Binary Search

  1. 35. Search Insert Position [EASY] (C++)
  2. 74. Search a 2D Matrix [MEDIUM] (C++)
  3. 162. Find Peak Element [MEDIUM] (C++)
  4. 33. Search in Rotated Sorted Array [MEDIUM] (C++)
  5. 34. Find First and Last Position of Element in Sorted Array [MEDIUM] (C++)
  6. 153. Find Minimum in Rotated Sorted Array [MEDIUM] (C++)
  7. 4. Median of Two Sorted Arrays [HARD] (C++)

Heap

  1. 215. Kth Largest Element in an Array [MEDIUM] (C++)
  2. 502. IPO [HARD] (C++)
  3. 373. Find K Pairs with Smallest Sums [MEDIUM] (C++)
  4. 295. Find Median from Data Stream [HARD] (C++)

Bit Manipulation

  1. 67. Add Binary [EASY] (C++)
  2. 190. Reverse Bits [EASY] (C++)
  3. 191. Number of 1 Bits [EASY] (C++)
  4. 136. Single Number [EASY] (C++)
  5. 137. Single Number II [MEDIUM] (C++)
  6. 201. Bitwise AND of Numbers Range [MEDIUM] (C++)

Math

  1. 9. Palindrome Number [EASY] (C++)
  2. 66. Plus One [EASY] (C++)
  3. 172. Factorial Trailing Zeroes [MEDIUM] (C++)
  4. 69. Sqrt(x) [EASY] (C++)
  5. 50. Pow(x, n) [MEDIUM] (C++)
  6. 149. Max Points on a Line [HARD] (C++)

1D DP

  1. 70. Climbing Stairs [EASY] (C++)
  2. 198. House Robber [MEDIUM] (C++)
  3. 139. Word Break [MEDIUM] (C++)
  4. 322. Coin Change [MEDIUM] (C++)
  5. 300. Longest Increasing Subsequence [MEDIUM] (C++)

Multidimensional DP

  1. 120. Triangle [MEDIUM] (C++)
  2. 64. Minimum Path Sum [MEDIUM] (C++)
  3. 63. Unique Paths II [MEDIUM] (C++)
  4. 5. Longest Palindromic Substring [MEDIUM] (C++)
  5. 97. Interleaving String [MEDIUM] (C++)
  6. 72. Edit Distance [MEDIUM] (C++)
  7. 123. Best Time to Buy and Sell Stock III [HARD] (C++)
  8. 188. Best Time to Buy and Sell Stock IV [HARD] (C++)
  9. 221. Maximal Square [MEDIUM] (C++)

Top 100 Liked

  • 100 most liked problems by LeetCoders.
  • Organized based on hot topics that help improve coding skills in interviews.

Backtracking

  1. 17. Letter Combinations of a Phone Number [MEDIUM] (C++)
  2. 22. Generate Parentheses [MEDIUM] (C++)
  3. 39. Combination Sum [MEDIUM] (C++)
  4. 46. Permutations [MEDIUM] (C++)
  5. 51. N-Queens [HARD]
  6. 78. Subsets [MEDIUM]
  7. 79. Word Search [MEDIUM] (C++)
  8. 131. Palindrome Partitioning [MEDIUM]

Binary Search

  1. 4. Median of Two Sorted Arrays [HARD] (C++)
  2. 33. Search in Rotated Sorted Array [MEDIUM] (C++)
  3. 34. Find First and Last Position of Element in Sorted Array [MEDIUM] (C++)
  4. 35. Search Insert Position [EASY] (C++)
  5. 74. Search a 2D Matrix [MEDIUM] (C++)
  6. 124. Binary Tree Maximum Path Sum [HARD] (C++)
  7. 153. Find Minimum in Rotated Sorted Array [MEDIUM] (C++)

Binary Tree

  1. 94. Binary Tree Inorder Traversal [EASY]
  2. 98. Validate Binary Search Tree [MEDIUM] (C++)
  3. 101. Symmetric Tree [EASY] (C++)
  4. 102. Binary Tree Level Order Traversal [MEDIUM] (C++)
  5. 104. Maximum Depth of Binary Tree [EASY] (C++)
  6. 105. Construct Binary Tree from Preorder and Inorder Traversal [MEDIUM] (C++)
  7. 108. Convert Sorted Array to Binary Search Tree [EASY] (C++)
  8. 114. Flatten Binary Tree to Linked List [MEDIUM] (C++)
  9. 199. Binary Tree Right Side View [MEDIUM] (C++)
  10. 226. Invert Binary Tree [EASY] (C++)
  11. 230. Kth Smallest Element in a BST [MEDIUM] (C++)
  12. 236. Lowest Common Ancestor of a Binary Tree [MEDIUM] (C++)
  13. 437. Path Sum III [MEDIUM] (C++)
  14. 543. Diameter of Binary Tree [EASY]

Dynamic Programming

  1. 5. Longest Palindromic Substring [MEDIUM] (C++)
  2. 32. Longest Valid Parentheses [HARD]
  3. 62. Unique Paths [MEDIUM]
  4. 64. Minimum Path Sum [MEDIUM] (C++)
  5. 70. Climbing Stairs [EASY] (C++)
  6. 72. Edit Distance [MEDIUM] (C++)
  7. 118. Pascal's Triangle [EASY]
  8. 139. Word Break [MEDIUM] (C++)
  9. 152. Maximum Product Subarray [MEDIUM]
  10. 198. House Robber [MEDIUM] (C++)
  11. 279. Perfect Squares [MEDIUM]
  12. 300. Longest Increasing Subsequence [MEDIUM] (C++)
  13. 322. Coin Change [MEDIUM] (C++)
  14. 416. Partition Equal Subset Sum [MEDIUM]
  15. 1143. Longest Common Subsequence [MEDIUM]

Graph

  1. 200. Number of Islands [MEDIUM] (C++)
  2. 207. Course Schedule [MEDIUM] (C++)
  3. 994. Rotting Oranges [MEDIUM] (C++)

Greedy

  1. 45. Jump Game II [MEDIUM] (C++)
  2. 55. Jump Game [MEDIUM] (C++)
  3. 121. Best Time to Buy and Sell Stock [EASY] (C++)
  4. 763. Partition Labels [MEDIUM]

Hashing

  1. 1. Two Sum [EASY] (C++)
  2. 49. Group Anagrams [MEDIUM] (C++)
  3. 128. Longest Consecutive Sequence [MEDIUM] (C++)
  4. 560. Subarray Sum Equals K [MEDIUM]

Heap

  1. 215. Kth Largest Element in an Array [MEDIUM] (C++)
  2. 295. Find Median from Data Stream [HARD] (C++)
  3. 347. Top K Frequent Elements [MEDIUM]

Linked Lists

  1. 2. Add Two Numbers [MEDIUM] (C++)
  2. 19. Remove Nth Node From End of List [MEDIUM] (C++)
  3. 21. Merge Two Sorted Lists [EASY] (C++)
  4. 23. Merge k Sorted Lists [HARD] (C++)
  5. 24. Swap Nodes in Pairs [MEDIUM]
  6. 25. Reverse Nodes in k-Group [HARD] (C++)
  7. 138. Copy List with Random Pointer [MEDIUM]
  8. 141. Linked List Cycle [EASY] (C++)
  9. 142. Linked List Cycle II [MEDIUM] (C++)
  10. 146. LRU Cache [MEDIUM] (C++)
  11. 148. Sort List [MEDIUM] (C++)
  12. 160. Intersection of Two Linked Lists [EASY]
  13. 206. Reverse Linked List [EASY] (C++)
  14. 234. Palindrome Linked List [EASY]

Matrix

  1. 48. Rotate Image [MEDIUM] (C++)
  2. 54. Spiral Matrix [MEDIUM] (C++)
  3. 73. Set Matrix Zeroes [MEDIUM] (C++)
  4. 240. Search a 2D Matrix II [MEDIUM]

Sliding Window

  1. 3. Longest Substring Without Repeating Characters [MEDIUM] (C++)
  2. 76. Minimum Window Substring [HARD] (C++)
  3. 239. Sliding Window Maximum [HARD] (C++)
  4. 438. Find All Anagrams in a String [MEDIUM] (C++)

Stack

  1. 20. Valid Parentheses [EASY] (C++)
  2. 84. Largest Rectangle in Histogram [HARD] (C++)
  3. 155. Min Stack [MEDIUM] (C++)
  4. 394. Decode String [MEDIUM] (C++)
  5. 739. Daily Temperatures [MEDIUM] (C++)

Two Pointers

  1. 11. Container With Most Water [MEDIUM] (C++)
  2. 15. 3Sum [MEDIUM] (C++)
  3. 42. Trapping Rain Water [HARD] (C++)
  4. 283. Move Zeroes [EASY] (C++)

Trie

  1. 208. Implement Trie (Prefix Tree) [MEDIUM] (C++)

Misc

  1. 31. Next Permutation [MEDIUM]
  2. 41. First Missing Positive [HARD] (C++)
  3. 53. Maximum Subarray [MEDIUM] (C++)
  4. 56. Merge Intervals [MEDIUM] (C++)
  5. 75. Sort Colors [MEDIUM]
  6. 136. Single Number [EASY] (C++)
  7. 169. Majority Element [EASY] (C++)
  8. 189. Rotate Array [MEDIUM] (C++)
  9. 238. Product of Array Except Self [MEDIUM] (C++)
  10. 287. Find the Duplicate Number [MEDIUM] (C++)

SQL 50

  • Basic to intermediate SQL topics
  • 50 essential SQL questions
  • Best for 1 month of prep time

Select

  1. 1757. Recyclable and Low Fat Products [EASY]
  2. 584. Find Customer Referee [EASY]
  3. 595. Big Countries [EASY]
  4. 1148. Article Views I [EASY]
  5. 1683. Invalid Tweets [EASY]

Basic Joins

  1. 1378. Replace Employee ID With The Unique Identifier [EASY]
  2. 1068. Product Sales Analysis I [EASY]
  3. 1581. Customer Who Visited but Did Not Make Any Transactions [EASY]
  4. 197. Rising Temperature [EASY]
  5. 1661. Average Time of Process per Machine [EASY]
  6. 577. Employee Bonus [EASY]
  7. 1280. Students and Examinations [EASY]
  8. 570. Managers with at Least 5 Direct Reports [MEDIUM]
  9. 1934. Confirmation Rate [MEDIUM]

Basic Aggregate Functions

  1. 620. Not Boring Movies [EASY]
  2. 1251. Average Selling Price [EASY]
  3. 1075. Project Employees I [EASY]
  4. 1633. Percentage of Users Attended a Contest [EASY]
  5. 1211. Queries Quality and Percentage [EASY]
  6. 1193. Monthly Transactions I [MEDIUM]
  7. 1174. Immediate Food Delivery II [MEDIUM]
  8. 550. Game Play Analysis IV [MEDIUM]

Sorting and Grouping

  1. 2356. Number of Unique Subjects Taught by Each Teacher [EASY]
  2. 1141. User Activity for the Past 30 Days I [EASY]
  3. 1070. Product Sales Analysis III [MEDIUM]
  4. 596. Classes More Than 5 Students [EASY]
  5. 1729. Find Followers Count [EASY]
  6. 619. Biggest Single Number [EASY]
  7. 1045. Customers Who Bought All Products [MEDIUM]

Advanced Select and Joins

  1. 1731. The Number of Employees Which Report to Each Employee [EASY]
  2. 1789. Primary Department for Each Employee [EASY]
  3. 610. Triangle Judgement [EASY]
  4. 180. Consecutive Numbers [MEDIUM]
  5. 1164. Product Price at a Given Date [MEDIUM]
  6. 1204. Last Person to Fit in the Bus [MEDIUM]
  7. 1907. Count Salary Categories [MEDIUM]

Subqueries

  1. 1978. Employees Whose Manager Left the Company [EASY]
  2. 626. Exchange Seats [MEDIUM]
  3. 1341. Movie Rating [MEDIUM]
  4. 1321. Restaurant Growth [MEDIUM]
  5. 602. Friend Requests II: Who Has the Most Friends [MEDIUM]
  6. 585. Investments in 2016 [MEDIUM]
  7. 185. Department Top Three Salaries [HARD]

Advanced String Functions / Regex / Clause

  1. 1667. Fix Names in a Table [EASY]
  2. 1527. Patients With a Condition [EASY]
  3. 196. Delete Duplicate Emails [EASY]
  4. 176. Second Highest Salary [MEDIUM]
  5. 1484. Group Sold Products By The Date [EASY]
  6. 1327. List the Products Ordered in a Period [EASY]
  7. 1517. Find Users With Valid E-Mails [EASY]