All LeetCode Questions List 题目汇总

All LeetCode Questions List（Part of Answers, still updating） 题目汇总及部分答案（持续更新中）

Leetcode problems classified by company 题目按公司分类(Last updated: October 2, 2017) .   Top Interview Questions

#	Title	Difficulty	Acceptance
1	Two Sum	Medium	17.70%
2	Add Two Numbers	Medium	21.10%
3	Longest Substring Without Repeating Characters	Medium	20.60%
4	Median of Two Sorted Arrays	Hard	17.40%
5	Longest Palindromic Substring	Medium	20.70%
6	ZigZag Conversion	Easy	21.80%
7	Reverse Integer	Easy	25.10%
8	String to Integer (atoi)	Easy	13.00%
9	Palindrome Number	Easy	28.30%
10	Regular Expression Matching	Hard	20.70%
11	Container With Most Water	Medium	32.00%
12	Integer to Roman	Medium	33.80%
13	Roman to Integer	Easy	34.00%
14	Longest Common Prefix	Easy	25.50%
15	3Sum	Medium	16.90%
16	3Sum Closest	Medium	26.90%
17	Letter Combinations of a Phone Number	Medium	25.80%
18	4Sum	Medium	21.70%
19	Remove Nth Node From End of List	Easy	27.10%
20	Valid Parentheses	Easy	26.50%
21	Merge Two Sorted Lists	Easy	32.70%
22	Generate Parentheses	Medium	32.60%
23	Merge k Sorted Lists	Hard	21.10%
24	Swap Nodes in Pairs	Medium	32.50%
25	Reverse Nodes in k-Group	Hard	25.50%
26	Remove Duplicates from Sorted Array	Easy	31.30%
27	Remove Element	Easy	32.10%
28	Implement strStr()	Easy	22.20%
29	Divide Two Integers	Medium	15.00%
30	Substring with Concatenation of All Words	Hard	19.40%
31	Next Permutation	Medium	25.00%
32	Longest Valid Parentheses	Hard	20.90%
33	Search in Rotated Sorted Array	Hard	28.80%
34	Search for a Range	Medium	27.50%
35	Search Insert Position	Medium	35.40%
36	Valid Sudoku	Easy	27.20%
37	Sudoku Solver	Hard	21.80%
38	Count and Say	Easy	25.20%
39	Combination Sum	Medium	27.90%
40	Combination Sum II	Medium	25.20%
41	First Missing Positive	Hard	22.90%
42	Trapping Rain Water	Hard	30.00%
43	Multiply Strings	Medium	21.00%
44	Wildcard Matching	Hard	15.00%
45	Jump Game II	Hard	24.20%
46	Permutations	Medium	31.90%
47	Permutations II	Hard	25.80%
48	Rotate Image	Medium	31.90%
49	Group Anagrams	Medium	24.30%
50	Pow(x, n)	Medium	26.70%
51	N-Queens	Hard	26.50%
52	N-Queens II	Hard	35.80%
53	Maximum Subarray	Medium	34.50%
54	Spiral Matrix	Medium	20.80%
55	Jump Game	Medium	27.00%
56	Merge Intervals	Hard	22.40%
57	Insert Interval	Hard	21.40%
58	Length of Last Word	Easy	28.00%
59	Spiral Matrix II	Medium	31.80%
60	Permutation Sequence	Medium	22.80%
61	Rotate List	Medium	21.70%
62	Unique Paths	Medium	32.80%
63	Unique Paths II	Medium	28.00%
64	Minimum Path Sum	Medium	32.20%
65	Valid Number	Hard	11.40%
66	Plus One	Easy	30.40%
67	Add Binary	Easy	24.70%
68	Text Justification	Hard	14.60%
69	Sqrt(x)	Medium	23.10%
70	Climbing Stairs	Easy	34.40%
71	Simplify Path	Medium	20.00%
72	Edit Distance	Hard	26.20%
73	Set Matrix Zeroes	Medium	31.40%
74	Search a 2D Matrix	Medium	31.60%
75	Sort Colors	Medium	32.60%
76	Minimum Window Substring	Hard	18.90%
77	Combinations	Medium	30.90%
78	Subsets	Medium	28.20%
79	Word Search	Medium	20.30%
80	Remove Duplicates from Sorted Array II	Medium	30.50%
81	Search in Rotated Sorted Array II	Medium	31.40%
82	Remove Duplicates from Sorted List II	Medium	25.00%
83	Remove Duplicates from Sorted List	Easy	34.50%
84	Largest Rectangle in Histogram	Hard	22.60%
85	Maximal Rectangle	Hard	22.00%
86	Partition List	Medium	27.50%
87	Scramble String	Hard	24.20%
88	Merge Sorted Array	Easy	29.70%
89	Gray Code	Medium	32.80%
90	Subsets II	Medium	27.70%
91	Decode Ways	Medium	16.40%
92	Reverse Linked List II	Medium	26.10%
93	Restore IP Addresses	Medium	21.00%
94	Binary Tree Inorder Traversal	Medium	36.20%
95	Unique Binary Search Trees II	Medium	28.00%
96	Unique Binary Search Trees	Medium	36.00%
97	Interleaving String	Hard	20.80%
98	Validate Binary Search Tree	Medium	20.60%
99	Recover Binary Search Tree	Hard	24.30%
100	Same Tree	Easy	41.80%
101	Symmetric Tree	Easy	31.60%
102	Binary Tree Level Order Traversal	Easy	29.30%
103	Binary Tree Zigzag Level Order Traversal	Medium	26.40%
104	Maximum Depth of Binary Tree	Easy	45.10%
105	Construct Binary Tree from Preorder and Inorder Traversal	Medium	26.40%
106	Construct Binary Tree from Inorder and Postorder Traversal	Medium	26.80%
107	Binary Tree Level Order Traversal II	Easy	31.10%
108	Convert Sorted Array to Binary Search Tree	Easy	46.5%
109	Convert Sorted List to Binary Search Tree	Medium	27.90%
110	Balanced Binary Tree	Easy	32.00%
111	Minimum Depth of Binary Tree	Easy	29.10%
112	Path Sum	Easy	29.80%
113	Path Sum II	Medium	26.60%
114	Flatten Binary Tree to Linked List	Medium	28.80%
115	Distinct Subsequences	Hard	26.30%
116	Populating Next Right Pointers in Each Node	Medium	36.20%
117	Populating Next Right Pointers in Each Node II	Hard	32.00%
118	Pascal's Triangle	Easy	30.10%
119	Pascal's Triangle II	Easy	29.40%
120	Triangle	Medium	27.40%
121	Best Time to Buy and Sell Stock	Medium	32.60%
122	Best Time to Buy and Sell Stock II	Medium	38.30%
123	Best Time to Buy and Sell Stock III	Hard	23.90%
124	Binary Tree Maximum Path Sum	Hard	21.50%
125	Valid Palindrome	Easy	22.00%
126	Word Ladder II	Hard	12.90%
127	Word Ladder	Medium	19.30%
128	Longest Consecutive Sequence	Hard	29.40%
129	Sum Root to Leaf Numbers	Medium	30.30%
130	Surrounded Regions	Medium	14.60%
131	Palindrome Partitioning	Medium	26.70%
132	Palindrome Partitioning II	Hard	19.70%
133	Clone Graph	Medium	24.00%
134	Gas Station	Medium	25.70%
135	Candy	Hard	20.50%
136	Single Number	Medium	45.10%
137	Single Number II	Medium	35.00%
138	Copy List with Random Pointer	Hard	25.10%
139	Word Break	Medium	23.00%
140	Word Break II	Hard	17.70%
141	Linked List Cycle	Medium	36.30%
142	Linked List Cycle II	Medium	31.40%
143	Reorder List	Medium	21.00%
144	Binary Tree Preorder Traversal	Medium	36.30%
145	Binary Tree Postorder Traversal	Hard	32.40%
146	LRU Cache	Hard	15.00%
147	Insertion Sort List	Medium	26.40%
148	Sort List	Medium	22.00%
149	Max Points on a Line	Hard	12.60%
150	Evaluate Reverse Polish Notation	Medium	21.10%
151	Reverse Words in a String	Medium	15.10%
152	Maximum Product Subarray	Medium	19.40%
153	Find Minimum in Rotated Sorted Array	Medium	33.30%
154	Find Minimum in Rotated Sorted Array II	Hard	31.90%
155	Min Stack	Easy	18.50%
156	Binary Tree Upside Down $	Medium	34.30%
157	Read N Characters Given Read4 $	Easy	29.80%
158	Read N Characters Given Read4 II - Call multiple times $	Hard	22.30%
159	Longest Substring with At Most Two Distinct Characters $	Hard	30.20%
160	Intersection of Two Linked Lists *	Easy	28.70%
161	One Edit Distance $	Medium	24.00%
162	Find Peak Element	Medium	31.50%
163	Missing Ranges $	Medium	24.10%
164	Maximum Gap	Hard	24.40%
165	Compare Version Numbers	Easy	15.20%
166	Fraction to Recurring Decimal	Medium	12.70%
167	Two Sum II - Input array is sorted	Medium	43.30%
168	Excel Sheet Column Title	Easy	18.10%
169	Majority Element	Easy	35.00%
170	Two Sum III - Data structure design $	Easy	24.70%
171	Excel Sheet Column Number	Easy	36.50%
172	Factorial Trailing Zeroes	Easy	28.40%
173	Binary Search Tree Iterator	Medium	29.30%
174	Dungeon Game	Hard	17.70%
175	Combine Two Tables @	Easy	34.40%
176	Second Highest Salary @	Easy	25.00%
177	Nth Highest Salary @	Medium	16.30%
178	Rank Scores @	Medium	24.60%
179	Largest Number @	Medium	15.70%
180	Consecutive Numbers @	Medium	26.60%
181	Employees Earning More Than Their Managers @	Easy	41.00%
182	Duplicate Emails @	Easy	38.10%
183	Customers Who Never Order @	Easy	33.70%
184	Department Highest Salary @	Medium	19.00%
185	Department Top Three Salaries @	Hard	15.20%
186	Reverse Words in a String II $	Medium	31.10%
187	Repeated DNA Sequences	Medium	19.50%
188	Best Time to Buy and Sell Stock IV	Hard	17.30%
189	Rotate Array	Easy	17.80%
190	Reverse Bits	Easy	28.40%
191	Number of 1 Bits	Easy	37.30%
192	Word Frequency #	Medium	26.10%
193	Valid Phone Numbers #	Easy	24.40%
194	Transpose File #	Medium	21.40%
195	Tenth Line #	Easy	32.20%
196	Delete Duplicate Emails	Easy	19.00%
197	Rising Temperature	Easy	25.90%
198	House Robber	Easy	28.80%
199	Binary Tree Right Side View	Medium	27.10%
200	Number of Islands	Medium	21.90%
201	Bitwise AND of Numbers Range	Medium	23.30%
202	Happy Number	Easy	31.40%
203	Remove Linked List Elements	Easy	25.80%
204	Count Primes	Easy	19.00%
205	Isomorphic Strings	Easy	24.20%
206	Reverse Linked List	Easy	31.50%
207	Course Schedule	Medium	21.70%
208	Implement Trie (Prefix Tree)	Medium	24.80%
209	Minimum Size Subarray Sum	Medium	22.90%
210	Course Schedule II	Medium	19.30%
211	Add and Search Word - Data structure design	Medium	20.70%
212	Word Search II	Hard	15.00%
213	House Robber II	Medium	26.30%
214	Shortest Palindrome	Hard	16.80%
215	Kth Largest Element in an Array	Medium	27.30%
216	Combination Sum III	Medium	27.70%
217	Contains Duplicate	Easy	35.90%
218	The Skyline Problem	Hard	16.20%
219	Contains Duplicate II	Easy	25.60%
220	Contains Duplicate III	Medium	15.30%
221	Maximal Square	Medium	20.30%
222	Count Complete Tree Nodes	Medium	19.40%
223	Rectangle Area	Easy	25.60%
224	Basic Calculator	Medium	15.80%
225	Implement Stack using Queues	Medium	29.60%
226	Invert Binary Tree	Easy	35.40%
227	Basic Calculator II	Medium	18.00%
228	Summary Ranges	Easy	21.10%
229	Majority Element II	Medium	30.50%
230	Kth Smallest Element in a BST	Medium	30.50%
231	Power of Two	Easy	31.30%
232	Implement Queue using Stacks	Easy	37.40%
233	Number of Digit One	Medium	16.10%
234	Palindrome Linked List	Easy	23.80%
235	Lowest Common Ancestor of a Binary Search Tree	Medium	38.90%
236	Lowest Common Ancestor of a Binary Tree	Medium	28.30%
237	Delete Node in a Linked List	Easy	50.90%
238	Product of Array Except Self	Medium	42.40%
239	Sliding Window Maximum	Hard	24.30%
240	Search a 2D Matrix II	Medium	31.40%
241	Different Ways to Add Parentheses	Medium	27.10%
242	Valid Anagram	Easy	39.30%
243	Shortest Word Distance $	Easy	41.80%
244	Shortest Word Distance II $	Medium	33.70%
245	Shortest Word Distance III $	Medium	43.20%
246	Strobogrammatic Number $	Easy	31.60%
247	Strobogrammatic Number II $	Medium	26.70%
248	Strobogrammatic Number III $	Hard	21.80%
249	Group Shifted Strings $	Easy	25.20%
250	Count Univalue Subtrees $	Medium	32.70%
251	Flatten 2D Vector $	Medium	28.30%
252	Meeting Rooms $	Easy	35.40%
253	Meeting Rooms II $	Medium	28.80%
254	Factor Combinations $	Medium	29.00%
255	Verify Preorder Sequence in Binary Search Tree$	Medium	32.30%
256	Paint House $	Medium	38.40%
257	Binary Tree Paths	Easy	21.90%
258	Add Digits	Easy	46.50%
259	3Sum Smaller $	Medium	34.20%
260	Single Number III	Medium	37.60%
261	Graph Valid Tree $	Medium	25.40%
262	Trips and Users	Hard	16.10%
263	Ugly Number	Easy	32.60%
264	Ugly Number II	Medium	21.60%
265	Paint House II $	Hard	30.00%
266	Palindrome Permutation $	Easy	45.80%
267	Palindrome Permutation II $	Medium	22.50%
268	Missing Number	Medium	34.70%
269	Alien Dictionary $	Hard	16.50%
270	Closest Binary Search Tree Value $	Easy	29.40%
271	Encode and Decode Strings $	Medium	25.40%
272	Closest Binary Search Tree Value II $	Hard	26.90%
273	Integer to English Words	Medium	15.50%
274	H-Index	Medium	25.30%
275	H-Index II	Medium	31.40%
276	Paint Fence $	Easy	25.00%
277	Find the Celebrity $	Medium	31.70%
278	First Bad Version	Easy	19.80%
279	Perfect Squares	Medium	28.80%
280	Wiggle Sort $	Medium	43.30%
281	Zigzag Iterator $	Medium	37.20%
282	Expression Add Operators	Hard	18.90%
283	Move Zeroes	Easy	41.40%
284	Peeking Iterator	Medium	31.00%
285	Inorder Successor in BST $	Medium	32.50%
286	Walls and Gates $	Medium	29.90%
287	Find the Duplicate Number	Hard	32.80%
288	Unique Word Abbreviation $	Easy	16.80%
289	Game of Life	Medium	32.60%
290	Word Pattern	Easy	26.50%
291	Word Pattern II $	Hard	31.50%
292	Nim Game	Easy	49.50%
293	Flip Game $	Easy	47.60%
294	Flip Game II $	Medium	38.10%
295	Find Median from Data Stream	Hard	18.60%
296	Best Meeting Point $	Hard	41.40%
297	Serialize and Deserialize Binary Tree	Medium	23.80%
298	Binary Tree Longest Consecutive Sequence $	Medium	32.20%
299	Bulls and Cows	Easy	23.80%
300	Longest Increasing Subsequence	Medium	31.50%
301	Remove Invalid Parentheses	Hard	27.00%
302	Smallest Rectangle Enclosing Black Pixels $	Hard	36.70%
303	Range Sum Query - Immutable	Easy	25.70%
304	Range Sum Query 2D - Immutable	Medium	21.50%
305	Number of Islands II $	Hard	26.70%
306	Additive Number	Medium	23.30%
307	Range Sum Query - Mutable	Medium	14.50%
308	Range Sum Query 2D - Mutable $	Hard	20.30%
309	Best Time to Buy and Sell Stock with Cooldown	Medium	32.60%
310	Minimum Height Trees	Medium	20.20%
311	Sparse Matrix Multiplication $	Medium	40.00%
312	Burst Balloons	Medium	24.50%
313	Super Ugly Number	Medium	31.20%
314	Binary Tree Vertical Order Traversal $	Medium	30.10%
315	Count of Smaller Numbers After Self	Hard	28.20%
316	Remove Duplicate Letters	Medium	23.00%
317	Shortest Distance from All Buildings $	Hard	29.10%
318	Maximum Product of Word Lengths	Medium	38.70%
319	Bulb Switcher	Medium	39.20%
320	Generalized Abbreviation $	Medium	40.40%
321	Create Maximum Number	Hard	19.10%
322	Coin Change	Medium	24.90%
323	Number of Connected Components in an Undirected Graph $	Medium	43.30%
324	Wiggle Sort II	Medium	20.10%
325	Maximum Size Subarray Sum Equals k $	Easy	39.60%
326	Power of Three	Easy	35.30%
327	Count of Range Sum	Hard	24.30%
328	Odd Even Linked List	Easy	37.80%
329	Longest Increasing Path in a Matrix	Medium	29.50%
330	Patching Array	Medium	28.80%
331	Verify Preorder Serialization of a Binary Tree	Medium	31.50%
332	Reconstruct Itinerary	Medium	23.40%
333	Largest BST Subtree $	Medium	26.50%
334	Increasing Triplet Subsequence	Medium	33.20%
335	Self Crossing	Medium	18.00%
336	Palindrome Pairs	Hard	18.70%
337	House Robber III	Medium	37.00%
338	Counting Bits	Medium	55.40%
339	Nested List Weight Sum $	Easy	54.60%
340	Longest Substring with At Most K Distinct Characters $	Hard	36.30%
341	Flatten Nested List Iterator	Medium	18.70%
342	Power of Four	Easy	34.10%
343	Integer Break	Medium	43.60%
344	Reverse String	Easy	58.90%
345	Reverse Vowels of a String	Easy	35.30%
346	Moving Average from Data Stream $	Easy	69.20%
347	Top K Frequent Elements	Medium	44.50%
348	Design Tic-Tac-Toe $	Medium	45.60%
349	Intersection of Two Arrays	Easy	47.80%
350	Intersection of Two Arrays II	Easy	41.50%
351	Android Unlock Patterns $	Medium	32.00%
352	Data Stream as Disjoint Intervals	Hard	34.40%
353	Design Snake Game $	Medium	19.80%
354	Russian Doll Envelopes	Hard	27.10%
355	Design Twitter	Medium	22.20%
356	Line Reflection $	Medium	28.70%
357	Count Numbers with Unique Digits	Medium	42.50%
358	Rearrange String k Distance Apart $	Hard	26.90%
359	Logger Rate Limiter $	Easy	56.00%
360	Sort Transformed Array $	Medium	40.80%
361	Bomb Enemy $	Medium	32.60%
362	Design Hit Counter $	Medium	48.30%
363	Max Sum of Rectangle No Larger Than K	Hard	27.00%
364	Nested List Weight Sum II $	Medium	47.20%
365	Water and Jug Problem	Medium	20.10%
366	Find Leaves of Binary Tree $	Medium	53.60%
367	Valid Perfect Square	Medium	36.60%
368	Largest Divisible Subset	Medium	32.00%
369	Plus One Linked List $	Medium	50.10%
370	Range Addition $	Medium	49.90%
371	Sum of Two Integers	Easy	54.00%
372	Super Pow	Medium	30.10%
373	Find K Pairs with Smallest Sums	Medium	25.50%
374	Guess Number Higher or Lower	Easy	31.70%
375	Guess Number Higher or Lower II	Medium	28.30%
376	Wiggle Subsequence	Medium	35.80%
377	Combination Sum IV	Medium	37.50%
378	Kth Smallest Element in a Sorted Matrix	Medium	40.20%
379	Design Phone Directory $	Medium	25.80%
380	Insert Delete GetRandom O(1)	Medium	33.80%
381	Insert Delete GetRandom O(1) - Duplicates allowed	Hard	30.90%
382	Linked List Random Node	Medium	48.60%
383	Ransom Note	Easy	44.60%
384	Shuffle an Array	Medium	45.50%
385	Mini Parser	Medium	26.90%
386	Lexicographical Numbers	Medium	31.00%
387	First Unique Character in a String	Easy	43.10%
388	Longest Absolute File Path	Medium	28.30%
389	Find the Difference	Easy	49.90%
390	Elimination Game	Medium	12.50%
391	Perfect Rectangle	Hard	13.30%
392	Is Subsequence	Medium	44.10%
393	UTF-8 Validation	Medium	33.00%
394	Decode String	Medium	38.60%
395	Longest Substring with At Least K Repeating Characters	Medium	32.50%
396	Rotate Function	Easy	28.40%
397	Integer Replacement	Easy	25.90%
398	Random Pick Index	Medium	30.40%
399	Evaluate Division	Medium	34.60%
400	Nth Digit	Easy	30.70%
401	Binary Watch	Easy	43.00%
402	Remove K Digits	Medium	25.90%
403	Frog Jump	Hard	31.70%
404	Sum of Left Leaves	Easy	46.20%
405	Convert a Number to Hexadecimal	Easy	41.80%
406	Queue Reconstruction by Height	Medium	54.10%
407	Trapping Rain Water II	Hard	33.10%
408	Valid Word Abbreviation $	Easy	26.20%
409	Longest Palindrome	Easy	44.90%
410	Split Array Largest Sum	Hard	25.00%
411	Minimum Unique Word Abbreviation $	Hard	25.60%
412	Fizz Buzz	Easy	57.50%
413	Arithmetic Slices	Medium	53.50%
414	Third Maximum Number	Easy	26.50%
415	Add Strings	Easy	41.50%
416	Partition Equal Subset Sum	Medium	36.80%
417	Pacific Atlantic Water Flow	Medium	31.10%
418	Sentence Screen Fitting $	Medium	25.10%
419	Battleships in a Board	Medium	59.30%
420	Strong Password Checker	Hard	22.10%
421	Maximum XOR of Two Numbers in an Array	Medium	36.40%
422	Valid Word Square $	Easy	36.40%
423	Reconstruct Original Digits from English	Medium	40.80%
424	Longest Repeating Character Replacement	Medium	38.10%
425	Word Squares $	Hard	40.10%
426	Convert Binary Search Tree to Sorted Doubly Linked List $	Medium	35.1%
427	Construct Quad Tree	Easy	48.4%
428	Serialize and Deserialize N-ary Tree $	Hard	42.0%
429	N-ary Tree Level Order Traversal	Easy	54.6%
430	Flatten a Multilevel Doubly Linked List	Medium	32.5%
431	Encode N-ary Tree to Binary Tree  $	Hard	47.9%
432	All O`one Data Structure	Hard	28.30%
433	Minimum Genetic Mutation	Medium	33.50%
434	Number of Segments in a String	Easy	38.40%
435	Non-overlapping Intervals	Medium	39.80%
436	Find Right Interval	Medium	42.30%
437	Path Sum III	Easy	38.60%
438	Find All Anagrams in a String	Easy	33.50%
439	Ternary Expression Parser $	Medium	49.40%
440	K-th Smallest in Lexicographical Order	Hard	21.50%
441	Arranging Coins	Easy	36.20%
442	Find All Duplicates in an Array	Medium	46.40%
444	Sequence Reconstruction $	Medium	20.50%
445	Add Two Numbers II	Medium	45.40%
446	Arithmetic Slices II - Subsequence	Hard	22.30%
447	Number of Boomerangs	Easy	42.20%
448	Find All Numbers Disappeared in an Array	Easy	58.30%
449	Serialize and Deserialize BST	Medium	41.20%
450	Delete Node in a BST	Medium	34.50%
451	Sort Characters By Frequency	Medium	50.90%
452	Minimum Number of Arrows to Burst Balloons	Medium	42.10%
453	Minimum Moves to Equal Array Elements	Easy	46.30%
454	4Sum II	Medium	42.80%
455	Assign Cookies	Easy	48.10%
456	132 Pattern	Medium	28.00%
457	Circular Array Loop	Medium	20.60%
458	Poor Pigs	Easy	40.70%
459	Repeated Substring Pattern	Easy	39.70%
460	LFU Cache	Hard	18.30%
461	Hamming Distance	Easy	73.20%
462	Minimum Moves to Equal Array Elements II	Medium	50.90%
463	Island Perimeter	Easy	56.70%
464	Can I Win	Medium	22.20%
465	Optimal Account Balancing $	Hard	29.20%
466	Count The Repetitions	Hard	24.20%
467	Unique Substrings in Wraparound String	Medium	29.90%
468	Validate IP Address	Medium	22.10%
469	Convex Polygon $	Medium	27.20%
471	Encode String with Shortest Length $	Hard	43.7%
472	Concatenated Words	Hard	29.20%
473	Matchsticks to Square	Medium	31.80%
474	Ones and Zeroes	Medium	34.90%
475	Heaters	Easy	30.20%
476	Number Complement	Easy	61.20%
477	Total Hamming Distance	Medium	44.10%
479	Largest Palindrome Product	Easy	23.90%
480	Sliding Window Median	Hard	31.00%
481	Magical String	Medium	46.20%
482	License Key Formatting	Easy	39.0%
483	Smallest Good Base	Hard	30.60%
484	Find Permutation $	Medium	50.50%
485	Max Consecutive Ones	Easy	55.30%
486	Predict the Winner	Medium	43.60%
487	Max Consecutive Ones II $	Medium	42.70%
488	Zuma Game	Hard	38.00%
489	Robot Room Cleaner $	Hard	48.0%
490	The Maze $	Medium	42.80%
491	Increasing Subsequences	Medium	39.30%
492	Construct the Rectangle	Easy	49.70%
493	Reverse Pairs	Hard	17.10%
494	Target Sum	Medium	44.40%
495	Teemo Attacking	Medium	51.90%
496	Next Greater Element I	Easy	58.80%
498	Diagonal Traverse	Medium	46.20%
499	The Maze III $	Hard	32.00%
500	Keyboard Row	Easy	60.20%
501	Find Mode in Binary Search Tree	Easy	39.40%
502	IPO	Hard	32.40%
503	Next Greater Element II	Medium	46.20%
504	Base 7	Easy	46.40%
505	The Maze II $	Medium	34.80%
506	Relative Ranks	Easy	48.50%
507	Perfect Number	Easy	32.70%
508	Most Frequent Subtree Sum	Medium	52.00%
513	Find Bottom Left Tree Value	Medium	55.60%
514	Freedom Trail	Hard	27.20%
515	Find Largest Value in Each Tree Row	Medium	52.70%
516	Longest Palindromic Subsequence	Medium	42.00%
517	Super Washing Machines	Hard	34.60%
518	Coin Change 2	Medium	33.20%
520	Detect Capital	Easy	54.20%
521	Longest Uncommon Subsequence I	Easy	50.70%
522	Longest Uncommon Subsequence II	Medium	28.10%
523	Continuous Subarray Sum	Medium	21.3
524	Longest Word in Dictionary through Deleting	Medium	40.20%
525	Contiguous Array	Medium	34.40%
526	Beautiful Arrangement	Medium	53.50%
527	Word Abbreviation $	Hard	33.90%
529	Minesweeper	Medium	52.00%
530	Minimum Absolute Difference in BST	Easy	48.00%
531	Lonely Pixel I $	Medium	50.20%
532	K-diff Pairs in an Array	Easy	27.20%
533	Lonely Pixel II $	Medium	38.90%
534	Design TinyURL	Medium	N/A
535	Encode and Decode TinyURL	Medium	76.10%
536	Construct Binary Tree from String $	Medium	36.30%
537	Complex Number Multiplication	Medium	65.90%
538	Convert BST to Greater Tree	Medium	52.70%
539	Minimum Time Difference	Medium	44.70%
540	Single Element in a Sorted Array	Medium	55.90%
541	Reverse String II	Easy	44.40%
542	01 Matrix	Medium	32.50%
543	Diameter of Binary Tree	Easy	42.70%
544	Output Contest Matches $	Medium	73.20%
545	Boundary of Binary Tree $	Medium	29.10%
546	Remove Boxes	Hard	29.60%
547	Friend Circles	Medium	49.00%
548	Split Array with Equal Sum $	Medium	30.80%
549	Binary Tree Longest Consecutive Sequence II $	Medium	38.10%
551	Student Attendance Record I	Easy	43.90%
552	Student Attendance Record II	Hard	28.50%
553	Optimal Division	Medium	55.20%
554	Brick Wall	Medium	42.70%
555	Split Concatenated Strings $	Medium	30.00%
556	Next Greater Element III	Medium	27.70%
557	Reverse Words in a String III	Easy	61.20%
558	Quad Tree Intersection	Easy	33.50%
559	Maximum Depth of N-ary Tree	Easy	61.00%
560	Subarray Sum Equals K	Medium	41.80%
561	Array Partition I	Easy	69.80%
562	Longest Line of Consecutive One in Matrix $	Medium	38.80%
563	Binary Tree Tilt	Easy	47.00%
564	Find the Closest Palindrome	Hard	16.60%
565	Array Nesting	Medium	50.00%
566	Reshape the Matrix	Easy	59.80%
567	Permutation in String	Medium	36.30%
568	Maximum Vacation Days $	Hard	36.1%
569	Median Employee Salary $	Hard	39.5%
570	Managers with at Least 5 Direct Reports  $	Medium	58.3%
571	Find Median Given Frequency of Numbers $	Hard	43.0%
572	Subtree of Another Tree	Easy	40.4%
573	Squirrel Simulation $	Medium	52.4%
574	Winning Candidate  $	Medium	34.1%
575	Distribute Candies	Easy	58.4%
576	Out of Boundary Paths	Medium	52.6%
577	Employee Bonus $	Easy	59.50%
578	Get Highest Answer Rate Question  $	Medium	31.8%
579	Find Cumulative Salary of an Employee  $	Hard	30.2%
580	Count Student Number in Departments $	Medium	39.3%
581	Shortest Unsorted Continuous Subarray	Easy	29.3%
582	Kill Process $	Medium	47.70%
583	Delete Operation for Two Strings	Medium	44.00%
584	Find Customer Referee  $	Easy	62.6%
585	Investments in 2016  $	Medium	44.4%
586	Customer Placing the Largest Number of Orders  $	Easy	61.6%
587	Erect the Fence	Hard	33.7%
588	Design In-Memory File System  $	Hard	36.4%
589	N-ary Tree Preorder Traversal	Easy	58.7%
590	N-ary Tree Postorder Traversal	Easy	60.6%
591	Tag Validator	Hard	31.4%
592	Fraction Addition and Subtraction	Medium	47.00%
593	Valid Square	Medium	39.20%
594	Longest Harmonious Subsequence	Easy	40.00%
595	Big Countries	Easy	71.70%
596	Classes More Than 5 Students	Easy	40.00%
597	Friend Requests I: Overall Acceptance Rate  $
598	Range Addition II	Easy	48.30%
599	Minimum Index Sum of Two Lists	Easy	48.00%
600	Non-negative Integers without Consecutive Ones	Hard	27.40%
601	Human Traffic of Stadium	Hard	33.6%
602	Friend Requests II: Who Has the Most Friends  $	Medium	42.1%
603	Consecutive Available Seats   $	Easy	54.0%
604	Design Compressed String Iterator  $	Easy	33.6%
605	Can Place Flowers	Easy	30.00%
606	Construct String from Binary Tree	Easy	51.80%
607	Sales Person  $	Easy	49.90%
608	Tree Node   $	Medium	54.00%
609	Find Duplicate File in System	Medium	52.50%
610	Triangle Judgement   $	Easy	58.7%
611	Valid Triangle Number	Medium	42.5%
612	Shortest Distance in a Plane  $	Medium	51.0%
613	Shortest Distance in a Line  $	Easy	70.4%
614	Second Degree Follower  $	Medium	23.0%
615	Average Salary: Departments VS Company  $	Hard	32.00%
616	Add Bold Tag in String  $	Medium	38.3%
617	Merge Two Binary Trees	Easy	68.4%
618	Students Report By Geography   $	Hard	40.0%
619	Biggest Single Number  $	Easy	36.2%
620	Not Boring Movies	Easy	59.5%
621	Task Scheduler	Medium	41.40%
622	Design Circular Queue	Medium	36.0%
623	Add One Row to Tree	Medium	46.2%
624	Maximum Distance in Arrays  $	Easy	32.70%
625	Minimum Factorization  $	Medium	29.50%
626	Exchange Seats	Medium	49.0%
627	Swap Salary	Easy	67.1%
628	Maximum Product of Three Numbers	Easy	45.40%
629	K Inverse Pairs Array	Hard	23.90%
630	Course Schedule III	Medium	20.50%
631	Design Excel Sum Formula  $	Hard	25.60%
632	Smallest Range	Hard	42.80%
633	Sum of Square Numbers	Easy	31.60%
634	Find the Derangement of An Array  $	Medium	32.70%
635	Design Log Storage System  $	Medium	47.70%
636	Exclusive Time of Functions	Medium	40.30%
637	Average of Levels in Binary Tree	Easy	55.60%
638	Shopping Offers	Medium	41.50%
639	Decode Ways II	Hard	22.80%
640	Solve the Equation	Medium	39.00%
641	Design Circular Deque	Medium	49.5%
642	Design Search Autocomplete System  $	Hard	29.40%
643	Maximum Average Subarray I	Easy	38.40%
644	Maximum Average Subarray II  $	Hard	20.30%
645	Set Mismatch	Easy	40.40%
646	Maximum Length of Pair Chain	Medium	47.40%
647	Palindromic Substrings	Medium	55.70%
648	Replace Words	Medium	48.40%
649	Dota2 Senate	Medium	35.60%
650	2 Keys Keyboard	Medium	42.70%
651	4 Keys Keyboard  $	Medium	46.70%
652	Find Duplicate Subtrees	Medium	33.20%
653	Two Sum IV - Input is a BST	Easy	50.60%
654	Maximum Binary Tree	Medium	70.80%
655	Print Binary Tree	Medium	50.80%
656	Coin Path  $	Hard	24.60%
657	Judge Route Circle	Easy	69.30%
658	Find K Closest Elements	Medium	36.30%
659	Split Array into Consecutive Subsequences	Medium	39.40%
660	Remove 9  $	Hard	46.10%
661	Image Smoother	Easy	46.60%
662	Maximum Width of Binary Tree	Medium	37.00%
663	Equal Tree Partition  $	Medium	36.70%
664	Strange Printer	Hard	31.10%
665	Non-decreasing Array	Easy	21.20%
666	Path Sum IV  $	Medium	48.90%
667	Beautiful Arrangement II	Medium	51.50%
668	Kth Smallest Number in Multiplication Table	Hard	36.30%
669	Trim a Binary Search Tree	Easy	58.70%
670	Maximum Swap	Medium	38.40%
671	Second Minimum Node In a Binary Tree	Easy	42.30%
672	Bulb Switcher II	Medium	47.60%
673	Number of Longest Increasing Subsequence	Medium	30.80%
674	Longest Continuous Increasing Subsequence	Easy	43.20%
675	Cut Off Trees for Golf Event	Hard	27.20%
676	Implement Magic Dictionary	Medium	50.70%
677	Map Sum Pairs	Medium	53.80%
678	Valid Parenthesis String	Medium	28.30%
679	24 Game	Hard	38.30%
680	Valid Palindrome II	Easy	31.10%
681	Next Closest Time  $	Medium	43.00%
682	Baseball Game	Easy	58.60%
683	K Empty Slots $	Hard	37.00%
684	Redundant Connection	Medium	37.40%
685	Redundant Connection II	Hard	28.40%
686	Repeated String Match	Easy	31.70%
687	Longest Univalue Path	Easy	32.90%
688	Knight Probability in Chessboard	Medium	38.90%
689	Maximum Sum of 3 Non-Overlapping Subarrays	Hard	41.70%
690	Employee Importance	Easy	53.60%
691	Stickers to Spell Word	Hard	32.30%
692	Top K Frequent Words	Medium	41.70%
693	Binary Number with Alternating Bits	Easy	54.20%
694	Number of Distinct Islands  $	Medium	43.90%
695	Max Area of Island	Easy	53.30%
696	Count Binary Substrings	Easy	51.90%
697	Degree of an Array	Easy	47.90%
698	Partition to K Equal Sum Subsets	Medium	35.60%
699	Falling Squares	Hard	36.80%
700	Search in a Binary Search Tree	Easy	61.0%
701	Insert into a Binary Search Tree	Medium	60.5%
702	Search in a Sorted Array of Unknown Size  $	Medium	38.6%
703	Kth Largest Element in a Stream	Easy	34.5%
704	Binary Search	Easy	33.7%
705	Design HashSet	Easy	35.7%
706	Design HashMap	Easy	42.6%
707	Design Linked List	Easy	16.6%
708	Insert into a Cyclic Sorted List  $	Medium	21.3%
709	To Lower Case	Easy	74.4%
710	Random Pick with Blacklist	Hard	29.4%
711	Number of Distinct Islands II  $	Hard	39.40%
712	Minimum ASCII Delete Sum for Two Strings	Medium	50.90%
713	Subarray Product Less Than K	Medium	32.90%
714	Best Time to Buy and Sell Stock with Transaction Fee	Medium	41.60%
715	Range Module	Hard	31.00%
716	Max Stack  $	Hard	35.50%
717	1-bit and 2-bit Characters	Easy	50.90%
718	Maximum Length of Repeated Subarray	Medium	39.90%
719	Find K-th Smallest Pair Distance	Hard	26.10%
720	Longest Word in Dictionary	Easy	40.60%
721	Accounts Merge	Medium	29.60%
722	Remove Comments	Medium	26.30%
723	Candy Crush  $	Medium	56.10%
724	Find Pivot Index	Easy	41.00%
725	Split Linked List in Parts	Medium	50.00%
726	Number of Atoms	Hard	45.00%
727	Minimum Window Subsequence  $	Hard	30.10%
728	Self Dividing Numbers	Easy	68.50%
729	My Calendar I	Medium	40.10%
730	Count Different Palindromic Subsequences	Hard	32.40%
731	My Calendar II	Medium	35.00%
732	My Calendar III	Hard	51.30%
733	Flood Fill	Easy	49.30%
734	Sentence Similarity  $	Easy	38.60%
735	Asteroid Collision	Medium	37.60%
736	Parse Lisp Expression	Hard	42.00%
737	Sentence Similarity II	Medium	41.20%
738	Monotone Increasing Digits	Medium	41.80%
739	Daily Temperatures	Medium	53.50%
740	Delete and Earn	Medium	42.60%
741	Cherry Pickup	Hard	22.50%
742	Closest Leaf in a Binary Tree  $	Medium	33.20%
743	Network Delay Time	Medium	34.30%
744	Find Smallest Letter Greater Than Target	Easy	45.30%
745	Prefix and Suffix Search	Hard	24.50%
746	Min Cost Climbing Stairs	Easy	43.60%
747	Largest Number At Least Twice of Others	Easy	42.60%
748	Shortest Completing Word	Medium	53.50%
749	Contain Virus	Hard	39.60%
750	Number Of Corner Rectangles  $	Medium	51.00%
751	IP to CIDR	Easy	54.80%
752	Open the Lock	Medium	38.0%
753	Cracking the Safe	Hard	39.6%
754	Reach a Number	Easy	25.7%
755	Pour Water  $	Medium	33.9%
756	Pyramid Transition Matrix	Medium	44.9%
757	Set Intersection Size At Least Two	Hard	34.5%
758	Bold Words in String  $	Easy	37.0%
759	Employee Free Time  $	Hard	51.7%
760	Find Anagram Mappings  $	Easy	75.1%
761	Special Binary String	Hard	39.4%
762	Prime Number of Set Bits in Binary Representation	Easy	55.4%
763	Partition Labels	Medium	64.8%
764	Largest Plus Sign	Medium	36.3%
765	Couples Holding Hands	Hard	47.8%
766	Toeplitz Matrix	Easy	59.1%
767	Reorganize String	Medium	38.4%
768	Max Chunks To Make Sorted (ver. 2)	Hard	43.8%
769	Max Chunks To Make Sorted (ver. 1)	Medium	48.9%
770	Basic Calculator IV	Hard	43.7%
771	Jewels and Stones	Easy	81.8%
772	Basic Calculator III   $	Hard	38.2%
773	Sliding Puzzle	Medium	47.1%
774	Minimize Max Distance to Gas Station  $	Hard	34.8%
775	Global and Local Inversions	Medium	35.3%
776	Split BST  $	Medium	49.8%
777	Swap Adjacent in LR String	Medium	49.8%
778	Swim in Rising Water	Hard	44.9%
779	K-th Symbol in Grammar	Easy	37.5%
780	Reaching Points	Hard	24.5%
781	Rabbits in Forest	Medium	49.9%
782	Transform to Chessboard	Hard	37.7%
783	Minimum Distance Between BST Nodes	Easy	48.4%
784	Letter Case Permutation	Easy	53.4%
785	Is Graph Bipartite?	Medium	39.7%
786	K-th Smallest Prime Fraction	Hard	34.5%
787	Cheapest Flights Within K Stops	Medium	30.3%
788	Rotated Digits	Easy	50.8%
789	Escape The Ghosts	Medium	52.8%
790	Domino and Tromino Tiling	Medium	33.6%
791	Custom Sort String	Medium	59.5%
792	Number of Matching Subsequences	Medium	37.9%
793	Preimage Size of Factorial Zeroes Function	hard	39.9%
794	Valid Tic-Tac-Toe State	Medium	27.9%
795	Number of Subarrays with Bounded Maximum	Medium	41.6%
796	Rotate String	Easy	49.1%
797	All Paths From Source to Target	Medium	67.2%
798	Smallest Rotation with Highest Score	Medium	36.1%
799	Champagne Tower	Medium	30.4%
800	Similar RGB Color  $	Easy	55.1%
801	Minimum Swaps To Make Sequences Increasing  *	Medium	32.1%
802	Find Eventual Safe States	Medium	40.9%
803	Bricks Falling When Hit	Hard	24.8%
804	Unique Morse Code Words	Easy	71.5%
805	Split Array With Same Average	Hard	22.3%
806	Number of Lines To Write String	Easy
807	Max Increase to Keep City Skyline	Medium
808	Soup Servings	Medium
809	Expressive Words	Medium
810	Chalkboard XOR Game	Hard
811	Subdomain Visit Count	Easy
812	Largest Triangle Area	Easy
813	Largest Sum of Averages	Medium
814	Binary Tree Pruning	Medium
815	Bus Routes	Hard	35.8%
816	Ambiguous Coordinates	Medium
817	Linked List Components	Medium
818	Race Car	Hard
819	Most Common Word	Easy	41.9%
820	Short Encoding of Words	Medium
821	Shortest Distance to a Character	Easy
822	Card Flipping Game	Medium
823	Binary Trees With Factors	Medium
824	Goat Latin	Easy
825	Friends Of Appropriate Ages	Medium
826	Most Profit Assigning Work	Medium
827	Making A Large Island	Hard
828	Unique Letter String	Hard
829	Consecutive Numbers Sum	Medium
830	Positions of Large Groups	Easy
831	Masking Personal Information	Medium
832	Flipping an Image
833	Find And Replace in String
834	Sum of Distances in Tree
835	Image Overlap
836	Rectangle Overlap
837	New 21 Game
838	Push Dominoes
839	Similar String Groups
840	Magic Squares In Grid
841	Keys and Rooms
842	Split Array into Fibonacci Sequence
843	Guess the Word	Hard	37.5%
844	Backspace String Compare	Easy	43.5%
845	Longest Mountain in Array	Medium
846	Hand of Straights	Medium
847	Shortest Path Visiting All Nodes	Hard
848	Shifting Letters
849	Maximize Distance to Closest Person
850	Rectangle Area II
851	Loud and Rich
852	Peak Index in a Mountain Array
853	Car Fleet	Medium	34.0%
854	K-Similar Strings	Hard
855	Exam Room	Medium	32.6%
856	Score of Parentheses
857	Minimum Cost to Hire K Workers	Hard	43.0%
858	Mirror Reflection
859	Buddy Strings
860	Lemonade Change
861	Score After Flipping Matrix
862	Shortest Subarray with Sum at Least K
863	All Nodes Distance K in Binary Tree
864	Shortest Path to Get All Keys
865	Smallest Subtree with all the Deepest Nodes
866	Prime Palindrome
867	Transpose Matrix
868	Binary Gap
869	Reordered Power of 2
870	Advantage Shuffle	Medium
871	Minimum Number of Refueling Stops	Hard
872	Leaf-Similar Trees
873	Length of Longest Fibonacci Subsequence	Medium
874	Walking Robot Simulation	Easy	28.2%
875	Koko Eating Bananas	Medium	41.4%
876	Middle of the Linked List
877	Stone Game
878	Nth Magical Number
879	Profitable Schemes
880	Decoded String at Index
881	Boats to Save People
882	Reachable Nodes In Subdivided Graph
883	Projection Area of 3D Shapes
884	Uncommon Words from Two Sentences
885	Spiral Matrix III
886	Possible Bipartition
887	Super Egg Drop
888	Fair Candy Swap
889	Construct Binary Tree from Preorder and Postorder Traversal
890	Find and Replace Pattern
891	Sum of Subsequence Widths
892	Surface Area of 3D Shapes
893	Groups of Special-Equivalent Strings
894	All Possible Full Binary Trees
895	Maximum Frequency Stack	Hard	48.3%
896	Monotonic Array	Easy	56.1%
897	Increasing Order Search Tree	Easy	56.9%
898	Bitwise ORs of Subarrays	Medium	28.7%
899	Orderly Queue	Hard	42.3%
900	RLE Iterator	Medium	39.1%
901	Online Stock Span	Medium	37.6%
902	Numbers At Most N Given Digit Set	Hard	23.8%
903	Valid Permutations for DI Sequence	Hard	36.0%
904	Fruit Into Baskets	Medium	34.2%
905	Sort Array By Parity	Easy	79.3%
906	Super Palindromes	Hard	21.3%
907	Sum of Subarray Minimums	Medium	13.6%
908	Smallest Range I	Easy	63.6%
909	Snakes and Ladders	Medium	24.6%
910	Smallest Range II	Medium	18.7%
911	Online Election	Medium	42.2%
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929	Unique Email Addresses	Easy	73.8%
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950