leetcode

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algorithms

#	Title	Solution	Difficulty
1	Two Sum	C++	Easy
2	Add Two Numbers	C++	Medium
3	Longest Substring Without Repeating Characters	C++	Medium
4	Median of Two Sorted Arrays	C++	Hard
5	Longest Palindromic Substring	C++	Medium
6	ZigZag Conversion	C++	Medium
7	Reverse Integer	C++	Easy
8	String to Integer (atoi)	C++	Medium
9	Palindrome Number	C++	Easy
10	Regular Expression Matching	C++ C++	Hard
11	Container With Most Water	C++	Medium
12	Integer to Roman	C++	Medium
13	Roman to Integer	C++	Easy
14	Longest Common Prefix	C++	Easy
15	3Sum	C++	Medium
16	3Sum Closest	C++	Medium
17	Letter Combinations of a Phone Number	C++	Medium
18	4Sum	C++	Medium
19	Remove Nth Node From End of List	C++	Medium
20	Valid Parentheses	C++	Easy
21	Merge Two Sorted Lists	C++	Easy
22	Generate Parentheses	C++	Medium
23	Merge k Sorted Lists	C++	Hard
24	Swap Nodes in Pairs	C++	Medium
25	Reverse Nodes in k-Group	C++	Hard
26	Remove Duplicates from Sorted Array	C++	Easy
27	Remove Element	C++	Easy
28	Implement strStr()	C++	Easy
29	Divide Two Integers	C++	Medium
30	Substring with Concatenation of All Words	C++	Hard
31	Next Permutation	C++	Medium
32	Longest Valid Parentheses	C++	Hard
33	Search in Rotated Sorted Array	C++	Medium
34	Find First and Last Position of Element in Sorted Array	C++	Medium
35	Search Insert Position	C++	Easy
36	Valid Sudoku	C++	Medium
38	Count and Say	C++	Easy
39	Combination Sum	C++	Medium
40	Combination Sum II	C++	Medium
41	First Missing Positive	C++	Hard
42	Trapping Rain Water	C++	Hard
43	Multiply Strings	C++	Medium
44	Wildcard Matching	C++	Hard
45	Jump Game II	C++	Hard
46	Permutations	C++	Medium
47	Permutations II	C++	Medium
48	Rotate Image	C++	Medium
49	Group Anagrams	C++	Medium
50	Pow(x, n)	C++	Medium
51	N-Queens	C++	Hard
52	N-Queens II	C++	Hard
53	Maximum Subarray	C++	Easy
54	Spiral Matrix	C++	Medium
55	Jump Game	C++	Medium
56	Merge Intervals	C++	Medium
57	Insert Interval	C++	Hard
58	Length of Last Word	C++	Easy
59	Spiral Matrix II	C++	Medium
60	Permutation Sequence	C++	Medium
61	Rotate List	C++	Medium
62	Unique Paths	C++C++	Medium
63	Unique Paths II	C++	Medium
64	Minimum Path Sum	C++C++	Medium
65	Valid Number	C++	Hard
66	Plus One	C++	Easy
67	Add Binary	C++	Easy
68	Text Justification	C++	Hard
69	Sqrt(x)	C++	Easy
70	Climbing Stairs	C++ C++ C++ C++	Easy
71	Simplify Path	C++	Medium
72	Edit Distance	C++	Hard
73	Set Matrix Zeroes	C++	Medium
74	Search a 2D Matrix	C++	Medium
75	Sort Colors	C++	Medium
76	Minimum Window Substring	C++	Hard
77	Combinations	C++	Medium
78	Subsets	C++C++	Medium
79	Word Search	C++	Medium
80	Remove Duplicates from Sorted Array II	C++	Medium
81	Search in Rotated Sorted Array II	C++	Medium
82	Remove Duplicates from Sorted List II	C++	Medium
83	Remove Duplicates from Sorted List	C++	Easy
84	Largest Rectangle in Histogram	C++	Hard
85	Maximal Rectangle	C++ C++	Hard
86	Partition List	C++	Medium
87	Scramble String	C++ C++	Hard
88	Merge Sorted Array	C++	Easy
89	Gray Code	C++ C++	Medium
90	Subsets II	C++	Medium
91	Decode Ways	C++ C++ C++	Medium
92	Reverse Linked List II	C++	Medium
93	Restore IP Addresses	C++	Medium
94	Binary Tree Inorder Traversal	C++ C++	Medium
95	Unique Binary Search Trees II	C++	Medium
96	Unique Binary Search Trees	C++	Medium
97	Interleaving String	C++ C++ C++	Hard
98	Validate Binary Search Tree	C++	Medium
99	Recover Binary Search Tree	C++	Hard
100	Same Tree	C++	Easy
101	Symmetric Tree	C++	Easy
102	Binary Tree Level Order Traversal	C++	Medium
103	Binary Tree Zigzag Level Order Traversal	C++	Medium
104	Maximum Depth of Binary Tree	C++	Easy
105	Construct Binary Tree from Preorder and Inorder Traversal	C++	Medium
106	Construct Binary Tree from Inorder and Postorder Traversal	C++	Medium
107	Binary Tree Level Order Traversal II	C++ C++	Easy
108	Convert Sorted Array to Binary Search Tree	C++	Easy
109	Convert Sorted List to Binary Search Tree	C++	Medium
110	Balanced Binary Tree	C++	Easy
111	Minimum Depth of Binary Tree	C++	Easy
112	Path Sum	C++	Easy
113	Path Sum II	C++ C++	Medium
114	Flatten Binary Tree to Linked List	C++	Medium
115	Distinct Subsequences	C++	Hard
116	Populating Next Right Pointers in Each Node	C++	Medium
117	Populating Next Right Pointers in Each Node II	C++	Medium
118	Pascal's Triangle	C++	Easy
119	Pascal's Triangle II	C++	Easy
120	Triangle	C++	Medium
121	Best Time to Buy and Sell Stock	C++	Easy
122	Best Time to Buy and Sell Stock II	C++	Easy
123	Best Time to Buy and Sell Stock III	C++ C++	Hard
124	Binary Tree Maximum Path Sum	C++	Hard
125	Valid Palindrome	C++	Easy
127	Word Ladder	C++	Medium
128	Longest Consecutive Sequence	C++	Hard
129	Sum Root to Leaf Numbers	C++	Medium
130	Surrounded Regions	C++	Medium
131	Palindrome Partitioning	C++	Medium
132	Palindrome Partitioning II	C++	Hard
133	Clone Graph	C++ C++	Medium
134	Gas Station	C++	Medium
135	Candy	C++	Hard
136	Single Number	C++	Easy
137	Single Number II	C++	Easy
138	Copy List with Random Pointer	C++	Medium
139	Word Break	C++	Medium
140	Word Break II	C++	Hard
141	Linked List Cycle	C++	Easy
142	Linked List Cycle II	C++	Medium
143	Reorder List	C++	Medium
144	Binary Tree Preorder Traversal	C++ C++	Medium
145	Binary Tree Postorder Traversal	C++ C++	Hard
146	LRU Cache	C++	Hard
147	Insertion Sort List	C++	Medium
148	Sort List	C++	Medium
149	Max Points on a Line	C++	Hard
150	Evaluate Reverse Polish Notation	C++	Medium
151	Reverse Words in a String	C++	Medium
152	Maximum Product Subarray	C++ C++	Medium
153	Find Minimum in Rotated Sorted Array	C++	Medium
154	Find Minimum in Rotated Sorted Array II	C++	Hard
155	Min Stack	C++	Easy
156	💰 Binary Tree Upside Down	C++ C++	Medium
157	💰 Read N Characters Given Read4	C++	Easy
158	💰 Read N Characters Given Read4 II - Call multiple times	C++	Hard
159	💰 Longest Substring with At Most Two Distinct Characters	C++	Hard
160	Intersection of Two Linked Lists	C++	Easy
161	💰 One Edit Distance	C++	Medium
162	Find Peak Element	C++	Medium
163	💰 Missing Ranges	C++	Medium
164	Maximum Gap	C++	Hard
165	Compare Version Numbers	C++	Medium
166	Fraction to Recurring Decimal	C++	Medium
167	Two Sum II - Input array is sorted	C++	Easy
168	Excel Sheet Column Title	C++ C++	Easy
169	Majority Element	C++ C++ C++ C++ C++ C++	Easy
170	💰 Two Sum III - Data structure design	C++	Easy
171	Excel Sheet Column Number	C++	Easy
172	Factorial Trailing Zeroes	C++	Easy
173	Binary Search Tree Iterator	C++	Medium
174	Dungeon Game	C++	Hard
179	Largest Number	C++	Medium
186	💰 Reverse Words in a String II	C++	Medium
187	Repeated DNA Sequences	C++	Medium
188	Best Time to Buy and Sell Stock IV	C++	Hard
189	Rotate Array	C++ C++ C++ C++	Easy
190	Reverse Bits	C++	Easy
191	Number of 1 Bits	C++ C++	Easy
198	House Robber	C++ C++ C++ C++	Easy
199	Binary Tree Right Side View	C++	Medium
200	Number of Islands	C++	Medium
201	Bitwise AND of Numbers Range	C++	Medium
202	Happy Number	C++ C++	Easy
203	Remove Linked List Elements	C++	Easy
204	Count Primes	C++	Easy
205	Isomorphic Strings	C++	Easy
206	Reverse Linked List	C++ C++	Easy
207	Course Schedule	C++ C++	Medium
208	Implement Trie (Prefix Tree)	C++	Medium
209	Minimum Size Subarray Sum	C++ C++ C++ C++	Medium
210	Course Schedule II	C++ C++	Medium
211	Add and Search Word - Data structure design	C++	Medium
212	Word Search II	C++	Hard
213	House Robber II	C++	Medium
214	Shortest Palindrome	C++ C++ C++	Hard
215	Kth Largest Element in an Array	C++ C++	Medium
216	Combination Sum III	C++	Medium
217	Contains Duplicate	C++	Easy
218	The Skyline Problem	C++	Hard
219	Contains Duplicate II	C++	Easy
220	Contains Duplicate III	C++	Medium
221	Maximal Square	C++ C++	Medium
222	Count Complete Tree Nodes	C++ C++	Medium
223	Rectangle Area	C++	Medium
224	Basic Calculator	C++	Hard
225	Implement Stack using Queues	C++ C++	Easy
226	Invert Binary Tree	C++ C++ C++	Easy
227	Basic Calculator II	C++	Medium
228	Summary Ranges	C++	Medium
229	Majority Element II	C++	Medium
230	Kth Smallest Element in a BST	C++ C++ C++ C++	Medium
231	Power of Two	C++	Easy
232	Implement Queue using Stacks	C++ C++	Easy
233	Number of Digit One	C++	Hard
234	Palindrome Linked List	C++ C++	Easy
235	Lowest Common Ancestor of a Binary Search Tree	C++ C++	Easy
236	Lowest Common Ancestor of a Binary Tree	C++	Medium
237	Delete Node in a Linked List	C++	Easy
238	Product of Array Except Self	C++	Medium
239	Sliding Window Maximum	C++	Hard
240	Search a 2D Matrix II	C++	Medium
241	Different Ways to Add Parentheses	C++ C++	Medium
242	Valid Anagram	C++	Easy
243	💰 Shortest Word Distance	C++	Easy
244	💰 Shortest Word Distance II	C++	Medium
245	💰 Shortest Word Distance III	C++	Medium
246	💰 Strobogrammatic Number	C++	Easy
247	💰 Strobogrammatic Number II	C++ C++	Medium
248	💰 Strobogrammatic Number III	C++	Hard
249	💰 Group Shifted Strings	C++	Medium
250	💰 Count Univalue Subtrees	C++	Medium
251	💰 Flatten 2D Vector	C++ C++	Medium
252	💰 Meeting Rooms	C++	Easy
253	💰 Meeting Rooms II	C++	Medium
254	💰 Factor Combinations	C++	Medium
255	💰 Verify Preorder Sequence in Binary Search Tree	C++ C++	Medium
256	💰 Paint House	C++	Easy
257	Binary Tree Paths	C++	Easy
258	Add Digits	C++	Easy
259	💰 3Sum Smaller	C++	Medium
260	Single Number III	C++	Medium
261	💰 Graph Valid Tree	C++ C++ C++	Medium
263	Ugly Number	C++	Easy
264	Ugly Number II	C++	Medium
265	💰 Paint House II	C++	Hard
266	💰 Palindrome Permutation	C++ C++	Easy
267	💰 Palindrome Permutation II	C++	Medium
268	Missing Number	C++ C++	Easy
269	💰 Alien Dictionary	C++ C++	Hard
270	💰 Closest Binary Search Tree Value	C++	Easy
271	💰 Encode and Decode Strings	C++	Medium
272	💰 Closest Binary Search Tree Value II	C++ C++	Hard
273	Integer to English Words	C++	Hard
274	H-Index	C++	Medium
275	H-Index II	C++	Medium
276	💰 Paint Fence	C++	Easy
277	💰 Find the Celebrity	C++	Medium
278	First Bad Version	C++	Easy
279	Perfect Squares	C++ C++	Medium
280	💰 Wiggle Sort	C++	Medium
281	💰 Zigzag Iterator	C++	Medium
282	Expression Add Operators	C++	Hard
283	Move Zeroes	C++	Easy
284	Peeking Iterator	C++	Medium
285	💰 Inorder Successor in BST	C++	Medium
286	💰 Walls and Gates	C++ C++	Medium
287	Find the Duplicate Number	C++	Medium
288	💰 Unique Word Abbreviation	C++	Medium
289	Game of Life	C++	Medium
290	Word Pattern	C++	Easy
291	💰 Word Pattern II	C++	Hard
292	Nim Game	C++	Easy
293	💰 Flip Game	C++	Easy
294	💰 Flip Game II	C++	Medium
295	Find Median from Data Stream	C++	Hard
296	💰 Best Meeting Point	C++	Hard
297	Serialize and Deserialize Binary Tree	C++ C++	Hard
298	💰 Binary Tree Longest Consecutive Sequence	C++	Medium
299	Bulls and Cows	C++	Medium
300	Longest Increasing Subsequence	C++ C++ C++ C++	Medium
301	Remove Invalid Parentheses	C++ C++	Hard
302	💰 Smallest Rectangle Enclosing Black Pixels	C++	Hard
303	Range Sum Query - Immutable	C++	Easy
304	Range Sum Query 2D - Immutable	C++	Medium
305	💰 Number of Islands II	C++	Hard
306	Additive Number	C++	Medium
307	Range Sum Query - Mutable	C++ C++	Medium
308	💰 Range Sum Query 2D - Mutable	C++	Hard
309	Best Time to Buy and Sell Stock with Cooldown	C++	Medium
310	Minimum Height Trees	C++	Medium
311	💰 Sparse Matrix Multiplication	C++	Medium
312	Burst Balloons	C++	Hard
313	Super Ugly Number	C++ C++	Medium
314	💰 Binary Tree Vertical Order Traversal	C++	Medium
315	Count of Smaller Numbers After Self	C++	Hard
316	Remove Duplicate Letters	C++	Hard
317	💰 Shortest Distance from All Buildings	C++	Hard
318	Maximum Product of Word Lengths	C++	Medium
319	Bulb Switcher	C++	Medium
320	💰 Generalized Abbreviation	C++	Medium
321	Create Maximum Number	C++	Hard
322	Coin Change	C++	Medium
323	💰 Number of Connected Components in an Undirected Graph	C++ C++	Medium
324	Wiggle Sort II	C++	Medium
325	💰 Maximum Size Subarray Sum Equals k	C++	Medium
326	Power of Three	C++ C++ C++	Easy
327	Count of Range Sum	C++ C++	Hard
328	Odd Even Linked List	C++	Medium
329	Longest Increasing Path in a Matrix	C++ C++	Hard
330	Patching Array	C++	Hard
331	Verify Preorder Serialization of a Binary Tree	C++	Medium
332	Reconstruct Itinerary	C++	Medium
333	💰 Largest BST Subtree	C++	Medium
334	Increasing Triplet Subsequence	C++	Medium
335	Self Crossing	C++	Hard
336	Palindrome Pairs	C++	Hard
337	House Robber III	C++ C++ C++	Medium
338	Counting Bits	C++	Medium
339	💰 Nested List Weight Sum	C++	Easy
340	💰 Longest Substring with At Most K Distinct Characters	C++	Hard
341	Flatten Nested List Iterator	C++	Medium
342	Power of Four	C++	Easy
343	Integer Break	C++	Medium
344	Reverse String	C++	Easy
345	Reverse Vowels of a String	C++	Easy
346	💰 Moving Average from Data Stream	C++	Easy
347	Top K Frequent Elements	C++	Medium
348	💰 Design Tic-Tac-Toe	C++	Medium
349	Intersection of Two Arrays	C++	Easy
350	Intersection of Two Arrays II	C++	Easy
351	💰 Android Unlock Patterns	C++	Medium
352	Data Stream as Disjoint Intervals	C++ C++	Hard
353	💰 Design Snake Game	C++	Medium
354	Russian Doll Envelopes	C++ C++	Hard
355	Design Twitter	C++	Medium
356	💰 Line Reflection	C++	Medium
357	Count Numbers with Unique Digits	C++ C++	Medium
358	💰 Rearrange String k Distance Apart	C++	Hard
359	💰 Logger Rate Limiter	C++	Easy
360	💰 Sort Transformed Array	C++	Medium
361	💰 Bomb Enemy	C++	Medium
362	💰 Design Hit Counter	C++	Medium
363	Max Sum of Rectangle No Larger Than K	C++	Hard
364	💰 Nested List Weight Sum II	C++	Medium
365	Water and Jug Problem	C++	Medium
366	💰 Find Leaves of Binary Tree	C++	Medium
367	Valid Perfect Square	C++	Easy
368	Largest Divisible Subset	C++	Medium
369	💰 Plus One Linked List	C++	Medium
370	💰 Range Addition	C++	Medium
371	Sum of Two Integers	C++	Easy
372	Super Pow	C++	Medium
373	Find K Pairs with Smallest Sums	C++	Medium
374	Guess Number Higher or Lower	C++	Easy
375	Guess Number Higher or Lower II	C++	Medium
376	Wiggle Subsequence	C++ C++ C++ C++ C++	Medium
377	Combination Sum IV	C++	Medium
378	Kth Smallest Element in a Sorted Matrix	C++ C++	Medium
379	💰 Design Phone Directory	C++	Medium
380	Insert Delete GetRandom O(1)	C++	Medium
381	Insert Delete GetRandom O(1) - Duplicates allowed	C++	Hard
382	Linked List Random Node	C++	Medium
383	Ransom Note	C++ C++	Easy
384	Shuffle an Array	C++	Medium
385	Mini Parser	C++	Medium
386	Lexicographical Numbers	C++	Medium
387	First Unique Character in a String	C++	Easy
388	Longest Absolute File Path	C++	Medium
389	Find the Difference	C++	Easy
390	Elimination Game	C++	Medium
391	Perfect Rectangle	C++	Hard
392	Is Subsequence	C++ C++	Easy
393	UTF-8 Validation	C++	Medium
394	Decode String	C++	Medium
395	Longest Substring with At Least K Repeating Characters	C++	Medium
396	Rotate Function	C++	Medium
397	Integer Replacement	C++ C++	Medium
398	Random Pick Index	C++	Medium
399	Evaluate Division	C++	Medium
400	Nth Digit	C++	Medium
401	Binary Watch	C++	Easy
402	Remove K Digits	C++	Medium
403	Frog Jump	C++ C++	Hard
404	Sum of Left Leaves	C++	Easy
405	Convert a Number to Hexadecimal	C++	Easy
406	Queue Reconstruction by Height	C++	Medium
407	Trapping Rain Water II	C++	Hard
408	💰 Valid Word Abbreviation	C++	Easy
409	Longest Palindrome	C++	Easy
410	Split Array Largest Sum	C++	Hard
411	💰 Minimum Unique Word Abbreviation	C++	Hard
412	Fizz Buzz	C++	Easy
413	Arithmetic Slices	C++	Medium
414	Third Maximum Number	C++	Easy
415	Add Strings	C++	Easy
416	Partition Equal Subset Sum	C++ C++ C++	Medium
417	Pacific Atlantic Water Flow	C++ C++	Medium
418	💰 Sentence Screen Fitting	C++	Medium
419	Battleships in a Board	C++	Medium
420	Strong Password Checker	C++	Hard
421	Maximum XOR of Two Numbers in an Array	C++	Medium
422	💰 Valid Word Square	C++	Easy
423	Reconstruct Original Digits from English	C++	Medium
424	Longest Repeating Character Replacement	C++	Medium
425	💰 Word Squares	C++	hard
426	💰 Convert Binary Search Tree to Sorted Doubly Linked List	C++	Medium
427	Construct Quad Tree	C++	Medium
428	💰 Serialize and Deserialize N-ary Tree	C++	Hard
429	N-ary Tree Level Order Traversal	C++	Easy
430	Flatten a Multilevel Doubly Linked List	C++ C++	Medium
431	💰 Encode N-ary Tree to Binary Tree	C++	Hard
432	All O`one Data Structure	C++	Hard
433	Minimum Genetic Mutation	C++	Medium
434	Number of Segments in a String	C++	Easy
435	Non-overlapping Intervals	C++	Medium
436	Find Right Interval	C++	Medium
437	Path Sum III	C++	Easy
438	Find All Anagrams in a String	C++ C++	Medium
439	💰 Ternary Expression Parser	C++	Medium
440	K-th Smallest in Lexicographical Order	C++	Hard
441	Arranging Coins	C++ C++	Easy
442	Find All Duplicates in an Array	C++	Medium
443	String Compression	C++	Easy
444	💰 Sequence Reconstruction	C++	Medium
445	Add Two Numbers II	C++	Medium
446	Arithmetic Slices II - Subsequence	C++	Hard
447	Number of Boomerangs	C++	Easy
448	Find All Numbers Disappeared in an Array	C++	Easy
449	Serialize and Deserialize BST	C++	Medium
450	Delete Node in a BST	C++	Medium
451	Sort Characters By Frequency	C++	Medium
452	Minimum Number of Arrows to Burst Balloons	C++	Medium
453	Minimum Moves to Equal Array Elements	C++	Easy
454	4Sum II	C++	Medium
455	Assign Cookies	C++	Easy
456	132 Pattern	C++	Medium
457	Circular Array Loop	C++	Medium
458	Poor Pigs	C++	Hard
459	Repeated Substring Pattern	C++	Easy
460	LFU Cache	C++	Hard
461	Hamming Distance	C++	Easy
462	Minimum Moves to Equal Array Elements II	C++	Medium
463	Island Perimeter	C++	Easy
464	Can I Win	C++	Medium
465	💰 Optimal Account Balancing	C++	Hard
466	Count The Repetitions	C++ C++	Hard
467	Unique Substrings in Wraparound String	C++	Medium
468	Validate IP Address	C++	Medium
469	💰 Convex Polygon	C++	Medium
470	Implement Rand10() Using Rand7()	C++	Medium
471	💰 Encode String with Shortest Length	C++	Hard
472	Concatenated Words	C++	Hard
473	Matchsticks to Square	C++ C++	Medium
474	Ones and Zeroes	C++	Medium
475	Heaters	C++	Easy
476	Number Complement	C++	Easy
477	Total Hamming Distance	C++	Medium
478	Generate Random Point in a Circle	C++	Medium
479	Largest Palindrome Product	C++	Hard
480	Sliding Window Median	C++	Hard
481	Magical String	C++	Medium
482	License Key Formatting	C++	Easy
483	Smallest Good Base	C++	Hard
484	💰 Find Permutation	C++	Medium
485	Max Consecutive Ones	C++	Easy
486	Predict the Winner	C++ C++ C++ C++	Medium
487	💰 Max Consecutive Ones II	C++	Medium
488	Zuma Game	C++	Hard
489	💰 Robot Room Cleaner	C++	Hard
490	💰 The Maze	C++ C++	Medium
491	Increasing Subsequences	C++	Medium
492	Construct the Rectangle	C++	Easy
493	Reverse Pairs	C++ C++ C++ C++	Hard
494	Target Sum	C++ C++ C++ C++	Medium
495	Teemo Attacking	C++	Medium
496	Next Greater Element I	C++	Easy
497	Random Point in Non-overlapping Rectangles	C++	Medium
498	Diagonal Traverse	C++	Medium
499	💰 The Maze III	C++ C++	Hard
500	Keyboard Row	C++	Easy
501	Find Mode in Binary Search Tree	C++	Easy
502	IPO	C++	Hard
503	Next Greater Element II	C++	Medium
504	Base 7	C++	Easy
505	💰 The Maze II	C++ C++ C++	Medium
506	Relative Ranks	C++ C++	Easy
507	Perfect Number	C++	Easy
508	Most Frequent Subtree Sum	C++	Medium
509	Fibonacci Number	C++ C++ C++ C++ C++ C++	Easy
510	💰 Inorder Successor in BST II	C++	Medium
513	Find Bottom Left Tree Value	C++	Medium
514	Freedom Trail	C++ C++	Hard
515	Find Largest Value in Each Tree Row	C++ C++	Medium
516	Longest Palindromic Subsequence	C++ C++ C++	Medium
517	Super Washing Machines	C++	Hard
518	Coin Change 2	C++ C++	Medium
519	Random Flip Matrix	C++	Medium
520	Detect Capital	C++	Easy
521	Longest Uncommon Subsequence I	C++	Easy
522	Longest Uncommon Subsequence II	C++	Medium
523	Continuous Subarray Sum	C++ C++	Medium
524	Longest Word in Dictionary through Deleting	C++	Medium
525	Contiguous Array	C++ C++	Medium
526	Beautiful Arrangement	C++	Medium
527	💰 Word Abbreviation	C++	Hard
528	Random Pick with Weight	C++	Medium
529	Minesweeper	C++ C++	Medium
530	Minimum Absolute Difference in BST	C++	Easy
531	💰 Lonely Pixel I	C++	Medium
532	K-diff Pairs in an Array	C++	Easy
533	💰 Lonely Pixel II	C++	Medium
535	Encode and Decode TinyURL	C++	Medium
536	💰 Construct Binary Tree from String	C++	Medium
537	Complex Number Multiplication	C++	Medium
538	Convert BST to Greater Tree	C++	Easy
539	Minimum Time Difference	C++	Medium
540	Single Element in a Sorted Array	C++	Medium
541	Reverse String II	C++	Easy
542	01 Matrix	C++ C++	Medium
543	Diameter of Binary Tree	C++	Easy
544	💰 Output Contest Matches	C++	Medium
545	💰 Boundary of Binary Tree	C++	Medium
546	Remove Boxes	C++	Hard
547	Friend Circles	C++ C++	Medium
548	💰 Split Array with Equal Sum	C++	Medium
549	💰 Binary Tree Longest Consecutive Sequence II	C++	Medium
551	Student Attendance Record I	C++	Easy
552	Student Attendance Record II	C++	Hard
553	Optimal Division	C++	Medium
554	Brick Wall	C++	Medium
555	💰 Split Concatenated Strings	C++	Medium
556	Next Greater Element III	C++ C++	Medium
557	Reverse Words in a String III	C++	Easy
558	Logical OR of Two Binary Grids Represented as Quad-Trees	C++	Medium
559	Maximum Depth of N-ary Tree	C++ C++	Easy
560	Subarray Sum Equals K	C++ C++ C++ C++	Medium
561	Array Partition I	C++	Easy
562	💰 Longest Line of Consecutive One in Matrix	C++	Medium
563	Binary Tree Tilt	C++	Easy
564	Find the Closest Palindrome	C++	Hard
565	Array Nesting	C++ C++ C++	Medium
566	Reshape the Matrix	C++	Easy
567	Permutation in String	C++ C++	Medium
568	💰 Maximum Vacation Days	C++ C++	Hard
572	Subtree of Another Tree	C++	Easy
573	💰 Squirrel Simulation	C++	Medium
575	Distribute Candies	C++	Easy
576	Out of Boundary Paths	C++ C++ C++	Easy
581	Shortest Unsorted Continuous Subarray	C++	Easy
582	💰 Kill Process	C++	Medium
583	Delete Operation for Two Strings	C++ C++ C++ C++ C++	Medium
587	Erect the Fence	C++	Hard
588	💰 Design In-Memory File System	C++	Hard
589	N-ary Tree Preorder Traversal	C++ C++	Easy
590	N-ary Tree Postorder Traversal	C++ C++	Easy
591	Tag Validator	C++	Hard
592	Fraction Addition and Subtraction	C++	Medium
593	Valid Square	C++	Medium
594	Longest Harmonious Subsequence	C++	Easy
598	Range Addition II	C++	Easy
599	Minimum Index Sum of Two Lists	C++	Easy
600	Non-negative Integers without Consecutive Ones	C++ C++ C++	Hard

sql

#	Title	Solution	Difficulty
175	Combine Two Tables	sql	Easy
176	Second Highest Salary	sql	Easy
177	Nth Highest Salary	sql	Medium
178	Rank Scores	sql	Medium
180	Consecutive Numbers	sql	Medium
181	Employees Earning More Than Their Managers	sql	Easy
182	Duplicate Emails	sql sql	Easy
183	Customers Who Never Order	sql	Easy
184	Department Highest Salary	sql	Medium
185	Department Top Three Salaries	sql	Hard
196	Delete Duplicate Emails	sql	Easy
197	Rising Temperature	sql	Easy
262	Trips and Users	sql	Hard
511	💰 Game Play Analysis I	sql	Easy
512	💰 Game Play Analysis II	sql	Easy
534	💰 Game Play Analysis III	sql	Medium
550	💰 Game Play Analysis IV	sql	Medium
569	💰 Median Employee Salary	sql	Hard
570	💰 Managers with at Least 5 Direct Reports	sql	Medium
571	💰 Find Median Given Frequency of Numbers	sql	Hard
574	💰 Winning Candidate	sql	Medium
577	💰 Employee Bonus	sql	Easy
578	💰 Get Highest Answer Rate Question	sql	Medium
579	💰 Find Cumulative Salary of an Employee	sql	Hard
580	💰 Count Student Number in Departments	sql	Medium
584	💰 Find Customer Referee	sql	Easy
585	💰 Investments in 2016	sql	Medium
586	💰 Customer Placing the Largest Number of Orders	sql	Easy
595	Big Countries	sql	Easy
596	Classes More Than 5 Students	sql	Easy
597	💰 Friend Requests I: Overall Acceptance Rate	sql	Easy

shell

#	Title	Solution	Difficulty
192	Word Frequency	shell	Medium
193	Valid Phone Numbers	shell shell shell	Easy
194	Transpose File	shell	Medium
195	Tenth Line	shell shell shell	Easy

To do

• Sudoku Solver
• Word Ladder II