1. Two Sum |
Python, JavaScript, C(++) |
Easy |
2. Add Two Numbers |
Python, JavaScript |
Medium |
3. Longest Substring Without Repeating Characters |
Python, JavaScript, C(++) |
Medium |
4. Median of Two Sorted Arrays |
JavaScript, C(++) |
Hard |
5. Longest Palindromic Substring |
Python, JavaScript, C(++) |
Medium |
6. ZigZag Conversion |
Python, C(++) |
Medium |
7. Reverse Integer |
Python |
Easy |
8. String to Integer (atoi) |
Python |
Medium |
9. Palindrome Number |
Python |
Easy |
10. Regular Expression Matching |
Python, JavaScript |
Hard |
11. Container With Most Water |
Python |
Medium |
12. Integer to Roman |
Python |
Medium |
13. Roman to Integer |
Python, JavaScript |
Easy |
14. Longest Common Prefix |
Python, C(++) |
Easy |
15. 3Sum |
Python |
Medium |
16. 3Sum Closest |
Python |
Medium |
17. Letter Combinations of a Phone Number |
Python |
Medium |
18. 4Sum |
Python |
Medium |
19. Remove Nth Node From End of List |
Python |
Medium |
20. Valid Parentheses |
Python, JavaScript |
Easy |
21. Merge Two Sorted Lists |
Python |
Easy |
22. Generate Parentheses |
Python |
Medium |
23. Merge k Sorted Lists |
Python, JavaScript |
Hard |
24. Swap Nodes in Pairs |
Python |
Medium |
25. Reverse Nodes in k-Group |
Python, JavaScript |
Hard |
26. Remove Duplicates from Sorted Array |
Python, JavaScript |
Easy |
27. Remove Element |
Python |
Easy |
28. Implement strStr() |
Python |
Easy |
29. Divide Two Integers |
Python |
Medium |
30. Substring with Concatenation of All Words |
Python |
Hard |
31. Next Permutation |
Python |
Medium |
32. Longest Valid Parentheses |
Python |
Hard |
33. Search in Rotated Sorted Array |
Python, JavaScript, C(++) |
Medium |
34. Find First and Last Position of Element in Sorted Array |
Python, JavaScript |
Medium |
35. Search Insert Position |
Python |
Easy |
36. Valid Sudoku |
Python |
Medium |
37. Sudoku Solver |
Python, Java |
Hard |
38. Count and Say |
Python |
Easy |
39. Combination Sum |
Python, JavaScript |
Medium |
40. Combination Sum II |
Python |
Medium |
41. First Missing Positive |
Python |
Hard |
42. Trapping Rain Water |
Python, JavaScript |
Hard |
43. Multiply Strings |
Python, C(++) |
Medium |
44. Wildcard Matching |
Python |
Hard |
45. Jump Game II |
Python |
Hard |
46. Permutations |
Python |
Medium |
47. Permutations II |
Python |
Medium |
48. Rotate Image |
Python |
Medium |
49. Group Anagrams |
Python, Java |
Medium |
50. Pow(x, n) |
Python |
Medium |
51. N-Queens |
Python |
Hard |
52. N-Queens II |
Python |
Hard |
53. Maximum Subarray |
Python, C(++) |
Easy |
54. Spiral Matrix |
Python |
Medium |
55. Jump Game |
Python |
Medium |
56. Merge Intervals |
Python, C(++) |
Medium |
57. Insert Interval |
Python, C(++) |
Hard |
58. Length of Last Word |
Python |
Easy |
59. Spiral Matrix II |
Python |
Medium |
60. Permutation Sequence |
Python |
Medium |
61. Rotate List |
Python |
Medium |
62. Unique Paths |
Python |
Medium |
63. Unique Paths II |
Python |
Medium |
64. Minimum Path Sum |
Python |
Medium |
66. Plus One |
Python |
Easy |
67. Add Binary |
Python |
Easy |
68. Text Justification |
Python |
Hard |
69. Sqrt(x) |
Python |
Easy |
70. Climbing Stairs |
Python |
Easy |
71. Simplify Path |
Python |
Medium |
72. Edit Distance |
Python |
Hard |
73. Set Matrix Zeroes |
Python |
Medium |
74. Search a 2D Matrix |
Python, JavaScript |
Medium |
75. Sort Colors |
Python |
Medium |
76. Minimum Window Substring |
Python, C(++) |
Hard |
77. Combinations |
Python |
Medium |
78. Subsets |
Python |
Medium |
79. Word Search |
Python |
Medium |
80. Remove Duplicates from Sorted Array II |
Python |
Medium |
81. Search in Rotated Sorted Array II |
Python |
Medium |
82. Remove Duplicates from Sorted List II |
Python |
Medium |
83. Remove Duplicates from Sorted List |
Python |
Easy |
84. Largest Rectangle in Histogram |
Python |
Hard |
86. Partition List |
Python |
Medium |
88. Merge Sorted Array |
Python, C(++) |
Easy |
89. Gray Code |
Python |
Medium |
90. Subsets II |
Python |
Medium |
91. Decode Ways |
Python |
Medium |
92. Reverse Linked List II |
Python |
Medium |
93. Restore IP Addresses |
Python |
Medium |
94. Binary Tree Inorder Traversal |
Python |
Medium |
95. Unique Binary Search Trees II |
Python |
Medium |
96. Unique Binary Search Trees |
Python |
Medium |
98. Validate Binary Search Tree |
Python |
Medium |
100. Same Tree |
Python |
Easy |
101. Symmetric Tree |
Python |
Easy |
102. Binary Tree Level Order Traversal |
Python, C(++) |
Medium |
103. Binary Tree Zigzag Level Order Traversal |
Python |
Medium |
104. Maximum Depth of Binary Tree |
Python |
Easy |
105. Construct Binary Tree from Preorder and Inorder Traversal |
Python |
Medium |
106. Construct Binary Tree from Inorder and Postorder Traversal |
Python |
Medium |
107. Binary Tree Level Order Traversal II |
Python |
Easy |
108. Convert Sorted Array to Binary Search Tree |
Python |
Easy |
109. Convert Sorted List to Binary Search Tree |
Python |
Medium |
110. Balanced Binary Tree |
Python |
Easy |
111. Minimum Depth of Binary Tree |
Python |
Easy |
112. Path Sum |
Python |
Easy |
113. Path Sum II |
Python |
Medium |
114. Flatten Binary Tree to Linked List |
Python |
Medium |
115. Distinct Subsequences |
Python |
Hard |
116. Populating Next Right Pointers in Each Node |
Python |
Medium |
120. Triangle |
Python |
Medium |
121. Best Time to Buy and Sell Stock |
Python |
Easy |
122. Best Time to Buy and Sell Stock II |
Python |
Easy |
123. Best Time to Buy and Sell Stock III |
Python |
Hard |
124. Binary Tree Maximum Path Sum |
Python |
Hard |
125. Valid Palindrome |
Python |
Easy |
128. Longest Consecutive Sequence |
Python |
Hard |
129. Sum Root to Leaf Numbers |
Python |
Medium |
130. Surrounded Regions |
Python |
Medium |
131. Palindrome Partitioning |
Python |
Medium |
132. Palindrome Partitioning II |
Python |
Hard |
133. Clone Graph |
Python |
Medium |
134. Gas Station |
Python |
Medium |
136. Single Number |
Python |
Easy |
137. Single Number II |
Python |
Medium |
139. Word Break |
Python, C(++) |
Medium |
140. Word Break II |
Python |
Hard |
141. Linked List Cycle |
Python |
Easy |
142. Linked List Cycle II |
Python |
Medium |
145. Binary Tree Postorder Traversal |
Python |
Hard |
146. LRU Cache |
Python |
Medium |
147. Insertion Sort List |
Python |
Medium |
148. Sort List |
Python |
Medium |
149. Max Points on a Line |
Python |
Hard |
150. Evaluate Reverse Polish Notation |
Python |
Medium |
151. Reverse Words in a String |
C(++) |
Medium |
153. Find Minimum in Rotated Sorted Array |
Python |
Medium |
154. Find Minimum in Rotated Sorted Array II |
Python |
Hard |
155. Min Stack |
Python |
Easy |
162. Find Peak Element |
Python |
Medium |
165. Compare Version Numbers |
Python |
Medium |
166. Fraction to Recurring Decimal |
Python |
Medium |
167. Two Sum II - Input array is sorted |
Python |
Easy |
169. Majority Element |
Python, JavaScript |
Easy |
173. Binary Search Tree Iterator |
Python, C(++) |
Medium |
174. Dungeon Game |
Python |
Hard |
179. Largest Number |
Python |
Medium |
187. Repeated DNA Sequences |
Python |
Medium |
189. Rotate Array |
Python |
Easy |
190. Reverse Bits |
C(++) |
Easy |
191. Number of 1 Bits |
Python |
Easy |
198. House Robber |
Python |
Easy |
200. Number of Islands |
Python |
Medium |
201. Bitwise AND of Numbers Range |
Python |
Medium |
202. Happy Number |
Python |
Easy |
204. Count Primes |
Python |
Easy |
205. Isomorphic Strings |
Python, JavaScript |
Easy |
206. Reverse Linked List |
Python |
Easy |
207. Course Schedule |
Python |
Medium |
208. Implement Trie (Prefix Tree) |
Python |
Medium |
209. Minimum Size Subarray Sum |
Python |
Medium |
210. Course Schedule II |
Python |
Medium |
211. Add and Search Word - Data structure design |
Python |
Medium |
212. Word Search II |
Python |
Hard |
213. House Robber II |
Python |
Medium |
214. Shortest Palindrome |
Python |
Hard |
215. Kth Largest Element in an Array |
Python, JavaScript |
Medium |
217. Contains Duplicate |
Python |
Easy |
219. Contains Duplicate II |
Python |
Easy |
220. Contains Duplicate III |
Python |
Medium |
221. Maximal Square |
Python |
Medium |
223. Rectangle Area |
Python |
Medium |
224. Basic Calculator |
C(++) |
Hard |
225. Implement Stack using Queues |
Python |
Easy |
226. Invert Binary Tree |
Python |
Easy |
227. Basic Calculator II |
Python |
Medium |
228. Summary Ranges |
Python |
Medium |
230. Kth Smallest Element in a BST |
Python |
Medium |
231. Power of Two |
Python |
Easy |
232. Implement Queue using Stacks |
Python, Java |
Easy |
235. Lowest Common Ancestor of a Binary Search Tree |
Python |
Easy |
236. Lowest Common Ancestor of a Binary Tree |
Python |
Medium |
237. Delete Node in a Linked List |
Python |
Easy |
238. Product of Array Except Self |
Python |
Medium |
239. Sliding Window Maximum |
Python |
Hard |
240. Search a 2D Matrix II |
Python |
Medium |
241. Different Ways to Add Parentheses |
Python |
Medium |
257. Binary Tree Paths |
Python |
Easy |
260. Single Number III |
Python |
Medium |
263. Ugly Number |
Python |
Easy |
264. Ugly Number II |
Python |
Medium |
268. Missing Number |
Python |
Easy |
273. Integer to English Words |
Python |
Hard |
274. H-Index |
Python |
Medium |
275. H-Index II |
Python |
Medium |
278. First Bad Version |
Python, C(++) |
Easy |
279. Perfect Squares |
Python |
Medium |
283. Move Zeroes |
Python |
Easy |
287. Find the Duplicate Number |
Python |
Medium |
289. Game of Life |
Python |
Medium |
290. Word Pattern |
Python |
Easy |
299. Bulls and Cows |
Python, JavaScript |
Easy |
300. Longest Increasing Subsequence |
Python |
Medium |
303. Range Sum Query - Immutable |
Python |
Easy |
304. Range Sum Query 2D - Immutable |
Python |
Medium |
305. Number of Islands II |
Python |
Hard |
307. Range Sum Query - Mutable |
Python |
Medium |
312. Burst Balloons |
C(++) |
Hard |
316. Remove Duplicate Letters |
C(++) |
Hard |
319. Bulb Switcher |
Python |
Medium |
322. Coin Change |
Python |
Medium |
326. Power of Three |
C(++) |
Easy |
329. Longest Increasing Path in a Matrix |
Python |
Hard |
331. Verify Preorder Serialization of a Binary Tree |
Python |
Medium |
332. Reconstruct Itinerary |
Python |
Medium |
337. House Robber III |
Python |
Medium |
338. Counting Bits |
Python |
Medium |
341. Flatten Nested List Iterator |
Python |
Medium |
343. Integer Break |
Python |
Medium |
347. Top K Frequent Elements |
Python |
Medium |
349. Intersection of Two Arrays |
Python |
Easy |
350. Intersection of Two Arrays II |
Python |
Easy |
354. Russian Doll Envelopes |
Python |
Hard |
355. Design Twitter |
Python |
Medium |
371. Sum of Two Integers |
Python |
Easy |
376. Wiggle Subsequence |
Python |
Medium |
378. Kth Smallest Element in a Sorted Matrix |
Python |
Medium |
387. First Unique Character in a String |
Python |
Easy |
392. Is Subsequence |
Python |
Easy |
394. Decode String |
Python |
Medium |
402. Remove K Digits |
Python |
Medium |
404. Sum of Left Leaves |
Python, C(++) |
Easy |
405. Convert a Number to Hexadecimal |
Python |
Easy |
406. Queue Reconstruction by Height |
Python |
Medium |
409. Longest Palindrome |
Python |
Easy |
416. Partition Equal Subset Sum |
Python |
Medium |
417. Pacific Atlantic Water Flow |
Python |
Medium |
421. Maximum XOR of Two Numbers in an Array |
Python |
Medium |
437. Path Sum III |
Python |
Easy |
438. Find All Anagrams in a String |
C(++) |
Medium |
441. Arranging Coins |
Python |
Easy |
442. Find All Duplicates in an Array |
Python |
Medium |
443. String Compression |
Python |
Easy |
445. Add Two Numbers II |
Python |
Medium |
452. Minimum Number of Arrows to Burst Balloons |
Python |
Medium |
454. 4Sum II |
Python, C(++) |
Medium |
455. Assign Cookies |
Python |
Easy |
458. Poor Pigs |
Python |
Hard |
459. Repeated Substring Pattern |
Python |
Easy |
461. Hamming Distance |
Python |
Easy |
462. Minimum Moves to Equal Array Elements II |
Python |
Medium |
463. Island Perimeter |
Python |
Easy |
464. Can I Win |
Python |
Medium |
465. Optimal Account Balancing |
Python |
Hard |
473. Matchsticks to Square |
Python |
Medium |
475. Heaters |
Python |
Easy |
476. Number Complement |
Python |
Easy |
477. Total Hamming Distance |
Python |
Medium |
481. Magical String |
Python |
Medium |
486. Predict the Winner |
Python |
Medium |
496. Next Greater Element I |
Python |
Easy |
504. Base 7 |
Python |
Easy |
507. Perfect Number |
Python |
Easy |
509. Fibonacci Number |
JavaScript |
Easy |
513. Find Bottom Left Tree Value |
Python |
Medium |
518. Coin Change 2 |
Python |
Medium |
525. Contiguous Array |
Python |
Medium |
526. Beautiful Arrangement |
Python |
Medium |
530. Minimum Absolute Difference in BST |
C(++) |
Easy |
542. 01 Matrix |
Python |
Medium |
543. Diameter of Binary Tree |
Python |
Easy |
547. Friend Circles |
Python, C(++) |
Medium |
551. Student Attendance Record I |
Python |
Easy |
554. Brick Wall |
Python |
Medium |
559. Maximum Depth of N-ary Tree |
Python |
Easy |
560. Subarray Sum Equals K |
Python |
Medium |
561. Array Partition I |
Python |
Easy |
566. Reshape the Matrix |
Python |
Easy |
576. Out of Boundary Paths |
Python |
Medium |
589. N-ary Tree Preorder Traversal |
Python |
Easy |
590. N-ary Tree Postorder Traversal |
Python |
Easy |
599. Minimum Index Sum of Two Lists |
Python |
Easy |
606. Construct String from Binary Tree |
Python, C(++) |
Easy |
617. Merge Two Binary Trees |
Python |
Easy |
621. Task Scheduler |
C(++) |
Medium |
628. Maximum Product of Three Numbers |
Python |
Easy |
633. Sum of Square Numbers |
Python |
Easy |
637. Average of Levels in Binary Tree |
C(++) |
Easy |
648. Replace Words |
Python |
Medium |
650. 2 Keys Keyboard |
Python |
Medium |
652. Find Duplicate Subtrees |
Python, C(++) |
Medium |
654. Maximum Binary Tree |
Python |
Medium |
655. Print Binary Tree |
Python |
Medium |
657. Robot Return to Origin |
Python |
Easy |
665. Non-decreasing Array |
JavaScript |
Easy |
669. Trim a Binary Search Tree |
Python |
Easy |
671. Second Minimum Node In a Binary Tree |
Python |
Easy |
673. Number of Longest Increasing Subsequence |
Python |
Medium |
674. Longest Continuous Increasing Subsequence |
Python |
Easy |
675. Cut Off Trees for Golf Event |
Python |
Hard |
677. Map Sum Pairs |
Python |
Medium |
680. Valid Palindrome II |
Python |
Easy |
682. Baseball Game |
Python |
Easy |
687. Longest Univalue Path |
Python |
Easy |
690. Employee Importance |
Python |
Easy |
692. Top K Frequent Words |
Python |
Medium |
697. Degree of an Array |
Python |
Easy |
701. Insert into a Binary Search Tree |
Python |
Medium |
703. Kth Largest Element in a Stream |
Python |
Easy |
704. Binary Search |
Python |
Easy |
705. Design HashSet |
Python |
Easy |
706. Design HashMap |
Python |
Easy |
717. 1-bit and 2-bit Characters |
Python |
Easy |
720. Longest Word in Dictionary |
Python |
Easy |
724. Find Pivot Index |
Python |
Easy |
728. Self Dividing Numbers |
Python |
Easy |
733. Flood Fill |
Python |
Easy |
743. Network Delay Time |
Python |
Medium |
744. Find Smallest Letter Greater Than Target |
Python |
Easy |
746. Min Cost Climbing Stairs |
Python |
Easy |
748. Shortest Completing Word |
Python |
Easy |
756. Pyramid Transition Matrix |
Python |
Medium |
762. Prime Number of Set Bits in Binary Representation |
Python |
Easy |
771. Jewels and Stones |
Python |
Easy |
778. Swim in Rising Water |
C(++) |
Hard |
784. Letter Case Permutation |
Python |
Easy |
799. Champagne Tower |
Python |
Medium |
801. Minimum Swaps To Make Sequences Increasing |
Python |
Medium |
802. Find Eventual Safe States |
Python |
Medium |
811. Subdomain Visit Count |
Python |
Easy |
823. Binary Trees With Factors |
Python |
Medium |
829. Consecutive Numbers Sum |
Python |
Hard |
836. Rectangle Overlap |
Python |
Easy |
841. Keys and Rooms |
Python |
Medium |
857. Minimum Cost to Hire K Workers |
Python |
Hard |
860. Lemonade Change |
Python |
Easy |
871. Minimum Number of Refueling Stops |
Python, C(++) |
Hard |
872. Leaf-Similar Trees |
Python |
Easy |
883. Projection Area of 3D Shapes |
Python |
Easy |
891. Sum of Subsequence Widths |
Python |
Hard |
897. Increasing Order Search Tree |
Python, JavaScript |
Easy |
905. Sort Array By Parity |
Python |
Easy |
912. Sort an Array |
JavaScript |
Medium |
930. Binary Subarrays With Sum |
Python |
Medium |
931. Minimum Falling Path Sum |
Python |
Medium |
958. Check Completeness of a Binary Tree |
Python |
Medium |
965. Univalued Binary Tree |
Python |
Easy |
987. Vertical Order Traversal of a Binary Tree |
JavaScript |
Medium |
988. Smallest String Starting From Leaf |
Python |
Medium |
1029. Two City Scheduling |
Python |
Easy |
1046. Last Stone Weight |
Python |
Easy |
1092. Shortest Common Supersequence |
Python |
Hard |
1109. Corporate Flight Bookings |
Python |
Medium |
1114. Print in Order |
C(++) |
Easy |
1115. Print FooBar Alternately |
C(++) |
Medium |
1129. Shortest Path with Alternating Colors |
Python |
Medium |
1145. Binary Tree Coloring Game |
Python |
Medium |
1160. Find Words That Can Be Formed by Characters |
Python |
Easy |
1175. Prime Arrangements |
Python |
Easy |
1202. Smallest String With Swaps |
Python |
Medium |
1278. Palindrome Partitioning III |
Python |
Hard |
1287. Element Appearing More Than 25% In Sorted Array |
Python |
Easy |
1288. Remove Covered Intervals |
Python |
Medium |
1289. Minimum Falling Path Sum II |
Python |
Hard |
1290. Convert Binary Number in a Linked List to Integer |
Python |
Easy |
1291. Sequential Digits |
Python |
Medium |
1292. Maximum Side Length of a Square with Sum Less than or Equal to Threshold |
Python |
Medium |
1293. Shortest Path in a Grid with Obstacles Elimination |
Python |
Hard |
1295. Find Numbers with Even Number of Digits |
C(++) |
Easy |
1296. Divide Array in Sets of K Consecutive Numbers |
Python |
Medium |
1297. Maximum Number of Occurrences of a Substring |
Python |
Medium |
1299. Replace Elements with Greatest Element on Right Side |
Python |
Easy |
1300. Sum of Mutated Array Closest to Target |
Python |
Medium |
1301. Number of Paths with Max Score |
Python |
Hard |
1304. Find N Unique Integers Sum up to Zero |
Python |
Easy |
1305. All Elements in Two Binary Search Trees |
Python |
Medium |
1306. Jump Game III |
Python |
Medium |
1312. Minimum Insertion Steps to Make a String Palindrome |
Python, C(++) |
Hard |
1317. Convert Integer to the Sum of Two No-Zero Integers |
Python |
Easy |
1319. Number of Operations to Make Network Connected |
Python |
Medium |
1323. Maximum 69 Number |
Python |
Easy |
1324. Print Words Vertically |
Python |
Medium |
1325. Delete Leaves With a Given Value |
Python |
Medium |
1326. Minimum Number of Taps to Open to Water a Garden |
Python |
Hard |
1328. Break a Palindrome |
C(++) |
Medium |
1329. Sort the Matrix Diagonally |
Python |
Medium |
1330. Reverse Subarray To Maximize Array Value |
Python |
Hard |
1331. Rank Transform of an Array |
C(++) |
Easy |
1332. Remove Palindromic Subsequences |
Python |
Easy |
1334. Find the City With the Smallest Number of Neighbors at a Threshold Distance |
C(++) |
Medium |
1337. The K Weakest Rows in a Matrix |
Python |
Easy |
1338. Reduce Array Size to The Half |
Python |
Medium |
1339. Maximum Product of Splitted Binary Tree |
Python |
Medium |
1356. Sort Integers by The Number of 1 Bits |
Python |
Easy |