LeetCode

This repo is build to collect leetcode algorithms we write.

Completion Statistic:

• Python: 383
• JavaScript: 25
• Java: 3
• C(++): 42

Total completed: 395

Solutions

Title	Solutions	Difficulty
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

Contribution

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