Solutions to Leetcode Problems in Multiple Languages

If you wish to contribute, a big thanks, feel free to send me a PR. If you wish to contribute in a different language that's great too, just update the index accordingly. There's also a list (non-leetcode) of questions that, I believe, shouldn't ever make it to a coding interview, but I've still solved them since I faced them multiple times.

Contents

#	Problem	Python	Java	C++	Javascript	SQL
1	Two Sum	x	x		x
2	Add Two Numbers	x	x		x
3	Longest Substring without Repeating Characters	x	x		x
4	Median of Two Sorted Arrays	x
5	Longest Palindromic Substring	x			x
6	Zig Zag Conversion	x
7	Reverse Integer	x			x
8	String to Integer	x
9	Palindrome Number	x
10	Regular Expression Matching	x
11	Container With Most Water	x
13	Roman to Integer	x
15	3Sum	x
17	Letter Combination of Phone Number	x
20	Valid Parantheses	x
21	Merge Two Sorted Lists	x
22	Generate Paratheses	x
23	Merge K Sorted Lists	x
24	Swap Nodes in Pairs	x
26	Remove Duplicates	x
31	Next Permutation	x
33	Search in a Rotated Array	x	x
34	Find First and Last Position of Element in Sorted Array	x
37	Sudoku Solver	x
42	Trapping Rain Water	x
44	Wildcard Matching	x
46	Permutations	x
48	Rotate Image	x
50	Pow(x,n)	x
51	N-Queens	x
53	Maximum Subarray Sum	x
54	Spiral Matrix	x
56	Merge Intervals	x
57	Insert Interval	x
66	Plus One	x
67	Add Binary	x
68	Text Justification	x
69	Sqrt(x)	x
70	Climbing Stairs	x
75	Sort Colors	x
76	Min Window Substring	x
78	Subsets	x
84	Largest Rectangle in Histogram	x
85	Maximal Rectangle	x
91	Decode Ways	x
94	Binary Tree Inorder Traversal	x
95	Unique Binary Search Trees -II	x
98	Validate Binary Search Tree	x
100	Same Tree	x
101	Symmetric Tree	x
102	Binary Tree Level Order Traversal	x
107	Binary Tree Level Order Traversal II	x
103	Binary Tree Zig Zag Level Order Traversal	x
104	Maximum Depth of Binary Tree	x
114	Flatten a Binary Tree to Linked List	x
116	Populating Next Right Pointers	x
117	Populating Next Right Pointers in Each Node II	x
118	Pascal's Triangle	x
121	Best Time to Buy & Sell Stock	x
125	Valid Palindrome	x
127	Word Ladder	x
128	Longest Consecutive Sequence	x
133	Clone Graph	x
138	Copy List of Random Pointer	x
139	Word Break	x	x
144	Binary Tree Preorder Traversal	x
145	Binary Tree Postorder Traversal	x
146	LRU Cache	x
150	Reverse Polish Notation	x
152	Maximum Product Subarray	x
155	Min Stack	x
156	Binary Tree Upside Down	x
157	Read N Characters Given Read4	x
158	Read N Characters Given Read4 II - Call multiple times	x
159	Longest Substring with At Most Two Distinct Characters	x
161	One Edit Distance	x
162	Find Peak Element	x
163	Missing Ranges	x
165	Compare Versions	x
168	Excel Sheet Column Title	x
170	Two Sum III - Data structure design	x
171	Excel Sheet Column Number	x
173	Binary Search Tree Iterator	x
175	Combine Two Tables					x
177	Nth Highest Salary					x
180	Consecutive Numbers					x
181	Employees Earning More Than Their Managers					x
182	Duplicate Emails					x
183	Customers Who Never Order					x
187	Repeated DNA Sequences	x
196	Delete Duplicate Emails					x
197	Rising Temperature	x
198	House Robber	x
199	Binary Tree Right Side View	x
200	Number of Islands	x	x
205	Isomorphic Strings	x	x
208	Implement Trie	x
210	Course Schedule II	x
211	Design Add and Search Word Data Structure	x
212	Word Search II	x
215	Kth Largest Element in an Array	x
221	Maximal Square	x
231	Power of Two	x
236	Lowest Common Ancestor of a Binary Tree	x
237	Delete Node in a Linked List	x
238	Product of Array Except Self	x
239	Sliding Window Maximum	x
240	Search a 2D matrix	x
243	Shortest Word Distance	x
244	Shortest Word Distance II	x
245	Shortest Word Distance III	x
246	Strobogrammatic Number	x
246	Strobogrammatic Number II	x
251	Flatten 2D Vector	x
252	Meeting Rooms	x
253	Meeting Rooms II	x
254	Factor Combinations	x
256	Paint House	x
257	Binary Tree Paths	x
259	3Sum Samller	x
266	Palindrome Permutation	x
270	Closest Binary Search Tree Value	x
271	Encode & Decode Strings	x
273	Integer to English Word	x
274	H Index	x
276	Paint Fence	x
277	Find Celebrity	x
278	First Bad Version	x
281	Zig Zag Interator	x
283	Move Zeroes	x
284	Peeking Interator	x
285	Inorder Successor	x
286	Walls and Gates	x
289	Game of Life	x
290	Word Pattern	x
295	Find Median from Data Stream	x
297	Serialize and Deserialize Binary Tree	x
298	Binary Tree Longest Consecutive Sequence	x
301	Remove Invalid Parentheses	x
312	Burst Balloons	x
314	Binary Tree Vertical Order Traversal	x
316	Remove Duplicate Letters	x
325	Maximum Size Subarray Sum Equals K	x
326	Power of Three	x
339	Nested List Weight Sum	x
340	Longest Substring with At Most K Distinct Characters	x
341	Flatten Nested List Iterator	x
345	Reverse Vowels of a String	x
346	Moving Average of a Data Stream	x
348	Design Tic Tac Toe	x
350	Intersection of Two Arrays II	x
357	Count Number of Unique Digits	x
359	Logger Rate Limiter	x
361	Bomb Enemy	x
364	Nested List Weighted Sum II	x
366	Find Leaves of a Binary Tree	x
367	Valid Perfect Square	x
373	Find K Pairs with Smallest Sums	x
380	Insert Delete GetRandom O(1)	x
383	Ransom Note	x
387	First Unique Character in a String	x
388	Longest Absolute File Path	x
392	Is Subsequence	x
404	Sum of Left Leaves	x
416	Partition Equal Subset Sum	x
418	Sentence Screen Fitting	x
419	Battleships in a Board	x
429	N-ary Tree Level Order Traversal	x
433	Minimum Genetic Mutation	x
437	Path Sum III	x
438	Find All Anagrams in a String	x
447	Number of Boomerangs	x
449	Serialize & Deserialize a BST	x
450	Delete a Node in a BST	x
451	Sort Characters by Frequency	x
459	Repeated Substring Pattern	x
460	LFU Cache	x
464	Can I Win	x
482	License Key Formatting	x
485	Maximum Consecutive Ones	x
501	Find Mode in Binary Search Tree	x
508	Most Frequent Subtree sum	x
509	Fibonacci Number	x
510	In Order Successor II	x
511	Game Play Analysis I					x
512	Game Play Analysis II					x
515	Largest Value in Each Tree Row	x
516	Longest Palindromic Subsequence	x
523	Continuous Subarray Sum	x
530	Minimum Absolute Difference	x			x
532	K-diff Pairs in an Array	x			x
534	Game Play Analysis III					x
535	Encode and Decode TinyURL	x
537	Complex Number Multiplication	x
540	Single Element in a Sorted Array	x
550	Game Play Analysis IV					x
574	Winning Candidate			x
589	N-ary Tree Preorder Traversal	x
590	N-ary Tree Postorder Traversal	x
595	Big Countries				x
597	Friend Requests I: Overall Acceptance Rate					x
605	Can Place Flowers	x
606	Construct String from Binary Tree	x
616	Add Bold Tags	x
617	Merge Two Binary Trees	x
619	Biggest Single Number				x
633	Sum of Square numbers	x
636	Exclusive Time Functions	x
637	Average of Levels in Binary Tree	x
640	Solve the Equation	x
645	Set Mismatch	x
646	Maximum Length of Pair Chain	x
647	Palindromic Substrings	x
653	Two Sum IV - Input is a BST	x
654	Maximum Binary Tree	x
681	Next Closest Time	x
682	Baseball Game	x
690	Employee Importance	x
702	Search In a Sorted Array of Unknown Size	x		x
708	Insert into a sorted circular Linked List	x
716	Max Stack	x
720	Longest Word in Dictionary			x
733	Flood Fill	x
734	Sentence Similarity		x
735	Asteroid Collision	x
737	Sentence Similarity II		x
746	Min Cost Climbing Stairs	x
776	Split BST			x
780	Reaching Points	x	[x](x
783	Minimum Distance Between BST Nodes	x			x
817	Linked List Components	x
824	Goat Latin				x
830	Positions of Large Groups	x
832	Flipping An Image	x
839	Similar String Groups	x			x
840	Magic Squares in a Grid	x
841	Keys and Rooms				x
844	Backspace String Compare	x
849	Maximize Distance to Closest Person	x
852	Peak Index in a Mountain Array	x
853	Car Fleet	x
854	K Similar Strings	x
859	Buddy Strings	x
864	Shortest Path to All Keys	x
865	Smallest Subtree with all the Deepest Nodes				x
896	Monotonic Array				x
921	Minimum Add to Make Paranthesis Valid	x			x
924	Minimize Malware Spread	x
937	Reorder Log Files				x
938	Range Sum of BST				x
953	Verify and Alien Dictionary				x
958	Check Completeness of Binary Tree	x			x
959	Regions Cut By Slashes	x
971	Flip Binary Tree To Match Preorder Traversal	x
973	K Closest Point to Origin				x
987	Vertical Order Traversal of a Binary Tree	x
990	Satisfiability of Equality Equations	x
994	Rotting Oranges	x
997	Find the Town Judge			x
1004	Maximum Consecutive Ones III		x
1008	Construct Binary Search Tree From Preorder Traversal		x
1021	Remove Outermost Parantheses		x
1022	Sum of Root to Leaf Numbers		x
1026	Maximum Difference Between Node and Ancestor	x
1027	Longest Arithmetic Sequence		x
1045	Customers Who Bought All Products					x
1050	Actors and Directors Who Cooperated At Least Three Times					x
1075	Project Employees I		x
1112	Highest Grade For Each Student		x
1114	Print in Order		x
1115	Print FooBar Alternately		x
1137	N-th Tribonacci Number	x
1145	Binary Tree Coloring Game	x	x
1165	Single Row Keyboard		x
1188	Bounded Blocking Queue		x
1241	Number of Comments per post		x
1303	Find the Team Size					x
1322	Ads Performance				x
1667	Fix Names in a Table					x
1757	Recyclable and Low Fat Products					x