kid0607 / LintCode

Java Solutions to problems on LintCode/LeetCode

Java Algorithm Problems

程序员的一天

从开始这个Github已经有将近两年时间, 很高兴这个repo可以帮到有需要的人. 我一直认为, 知识本身是无价的, 因此每逢闲暇, 我就会来维护这个repo, 给刷题的朋友们一些我的想法和见解. 下面来简单介绍一下这个repo:

README.md: 所有所做过的题目

ReviewPage.md: 所有题目的总结和归纳（不断完善中）

KnowledgeHash2.md: 对所做过的知识点的一些笔记

SystemDesign.md: 对系统设计的一些笔记

Future Milestone: 我准备将一些有意思的题目，做成视频的形式给大家参考

希望大家学习顺利, 对未来充满希望(程序员也是找到好老板的!) 有问题可以给我写邮件([e-mail]), 或者在GitHub上发issue给我.

Squence	Problem	Level	Language	Tags	Video Tutorial
0	Anagrams.java	Medium	Java	[]
1	Binary Representation.java	Hard	Java	[]
2	Binary Tree Level Order Traversal II.java	Medium	Java	[]
3	Binary Tree Level Order Traversal.java	Medium	Java	[]
4	Binary Tree Longest Consecutive Sequence.java	Medium	Java	[]
5	Binary Tree Maximum Path Sum II.java	Medium	Java	[]
6	Binary Tree Right Side View.java	Medium	Java	[]
7	Binary Tree Serialization.java	Medium	Java	[]
8	Binary Tree Zigzag Level Order Traversal.java	Medium	Java	[]
9	ColorGrid.java	Medium	Java	[]
10	Combination Sum II.java	Medium	Java	[]
11	Combination Sum.java	Medium	Java	[]
12	Combinations.java	Medium	Java	[]
13	Construct Binary Tree from Inorder and Postorder Traversal.java	Medium	Java	[]
14	Container With Most Water.java	Medium	Java	[]
15	Convert Binary Search Tree to Doubly Linked List.java	Medium	Java	[BST]
16	Copy List with Random Pointer.java	Medium	Java	[]
17	Count of Smaller Number before itself.java	Hard	Java	[]
18	Count of Smaller Number.java	Medium	Java	[]
19	Delete Digits.java	Medium	Java	[]
20	Encode and Decode Strings.java	Medium	Java	[]
21	Fast Power.java	Medium	Java	[]
22	Find the Connected Component in the Undirected Graph.java	Medium	Java	[]
23	Find the Weak Connected Component in the Directed Graph.java	Medium	Java	[]
24	Flatten 2D Vector.java	Medium	Java	[]
25	Fraction to Recurring Decimal.java	Medium	Java	[]
26	Generate Parentheses.java	Medium	Java	[]
27	Gray Code.java	Medium	Java	[]
28	Group Shifted Strings.java	Easy	Java	[]
29	H-Index II.java	Medium	Java	[]
30	H-Index.java	Medium	Java	[]
31	Hamming Distance.java	Easy	Java	[]
32	Happy Number.java	Easy	Java	[]
33	HashHeap.java	Hard	Java	[]
34	HashWithArray.java	Easy	Java	[]
35	HashWithCustomizedClass(LinkedList).java	Medium	Java	[]
36	Heapify.java	Medium	Java	[]
37	Heaters.java	Easy	Java	[]
38	Implement Trie (Prefix Tree).java	Medium	Java	[]
39	IndexMatch.java	Easy	Java	[]
40	Inorder Successor in Binary Search Tree.java	Medium	Java	[BST]
41	Insert Interval.java	Easy	Java	[]
42	Insert Node in a Binary Search Tree .java	Easy	Java	[BST]
43	Intersection of Two Arrays.java	Easy	Java	[]
44	Intersection of Two Linked Lists.java	Easy	Java	[Linked List]
45	Interval Minimum Number.java	Medium	Java	[]
46	Interval Sum II.java	Hard	Java	[]
47	Interval Sum.java	Medium	Java	[]
48	Isomorphic Strings.java	Easy	Java	[]
49	Jewels and Stones.java	Easy	Java	[Hash Table]
50	Kth Largest Element.java	Medium	Java	[]
51	Kth Smallest Element in a BST.java	Medium	Java	[BST]
52	Kth Smallest Sum In Two Sorted Arrays.java	Hard	Java	[]
53	Longest Common Prefix.java	Medium	Java	[]
54	Longest Palindromic Substring.java	Medium	Java	[]
55	Longest Univalue Path.java	Easy	Java	[]
56	Longest Word in Dictionary.java	Easy	Java	[]
57	LRU Cache.java	Hard	Java	[]
58	Majority Number II.java	Medium	Java	[]
59	Majority Number III.java	Medium	Java	[]
60	Matrix Zigzag Traversal.java	Easy	Java	[]
61	Max Area of Island.java	Easy	Java	[]
62	Maximum Subarray III.java	Hard	Java	[]
63	Median of two Sorted Arrays.java	Hard	Java	[]
64	Merge k Sorted Arrays.java	Medium	Java	[]
65	Merge k Sorted Lists.java	Medium	Java	[]
66	Merge Sorted Array II.java	N/A	Java	[]
67	Minimum Absolute Difference in BST.java	Easy	Java	[BST]
68	Minimum Height Trees.java	Medium	Java	[]
69	Minimum Subarray.java	N/A	Java	[]
70	Missing Ranges.java	Medium	Java	[]
71	Multiply Strings.java	Medium	Java	[]
72	Next Permutation.java	Medium	Java	[]
73	Nth to Last Node in List.java	N/A	Java	[]
74	Number Triangles.java	N/A	Java	[]
75	O(1) Check Power of 2.java	N/A	Java	[]
76	Paint Fence.java	Easy	Java	[]
77	Palindrome Permutation II.java	Medium	Java	[]
78	Partition Array by Odd and Even.java	N/A	Java	[]
79	Partition Array.java	N/A	Java	[]
80	Partition List.java	Medium	Java	[]
81	Pascal's Triangle II.java	Easy	Java	[]
82	Peeking Iterator.java	Medium	Java	[BST]
83	Permutation Index.java	Easy	Java	[]
84	Permutation Sequence.java	Medium	Java	[]
85	Permutations.java	Medium	Java	[]
86	Populating Next Right Pointers in Each Node II.java	Hard	Java	[]
87	Product of Array Exclude Itself.java	N/A	Java	[]
88	QuickSort.java	Easy	Java	[]
89	Recover Rotated Sorted Array.java	N/A	Java	[]
90	Rehashing.java	Medium	Java	[]
91	Remove Duplicates from Sorted Array.java	Easy	Java	[]
92	Remove Duplicates from Sorted List II.java	Medium	Java	[]
93	Remove Duplicates from Sorted List.java	Easy	Java	[]
94	Remove Duplicates from Unsorted List.java	N/A	Java	[]
95	Remove Invalid Parentheses.java	Hard	Java	[]
96	Remove Node in Binary Search Tree.java	Hard	Java	[BST]
97	Reorder List.java	Medium	Java	[]
98	Reshape the Matrix.java	Easy	Java	[]
99	Restore IP Addresses.java	Medium	Java	[]
100	Reverse String.java	Easy	Java	[]
101	Reverse Words in a String II.java	Medium	Java	[]
102	Reverse Words in a String.java	Medium	Java	[]
103	Roman to Integer.java	Easy	Java	[]
104	Rotate Image.java	Medium	Java	[]
105	Rotate List.java	Medium	Java	[]
106	Rotate String.java	Easy	Java	[]
107	Search a 2D Matrix II.java	Medium	Java	[]
108	Search a 2D Matrix.java	Medium	Java	[]
109	Search for a Range.java	Medium	Java	[]
110	Search Insert Position.java	Easy	Java	[]
111	Search Range in Binary Search Tree .java	Medium	Java	[BST]
112	Search Rotated in Sorted Array II.java	N/A	Java	[]
113	Search Rotated in Sorted Array.java	Hard	Java	[]
114	Segment Tree Build II.java	Medium	Java	[]
115	Segment Tree Build.java	Medium	Java	[]
116	Segment Tree Modify.java	Medium	Java	[]
117	Segment Tree Query II.java	Medium	Java	[]
118	Segment Tree Query.java	Medium	Java	[]
119	Serilization and Deserialization Of Binary Tree.java	N/A	Java	[]
120	Shortest Word Distance.java	Easy	Java	[]
121	Single Number II.java	Medium	Java	[]
122	Single Number III.java	Medium	Java	[]
123	Single Number.java	Easy	Java	[]
124	Sliding Window Maximum.java	Hard	Java	[]
125	Sort Color.java	Medium	Java	[]
126	Sort Colors II.java	N/A	Java	[]
127	Sort Letters by Case.java	N/A	Java	[]
128	Sort List.java	Medium	Java	[]
129	Space Replacement.java	N/A	Java	[]
130	Stone Game.java	N/A	Java	[]
131	String Permutation.java	Easy	Java	[]
132	String to Integer(atoi).java	Easy	Java	[]
133	Strobogrammatic Number II.java	Medium	Java	[]
134	Strobogrammatic Number.java	Easy	Java	[]
135	Subarray Sum Closest.java	Medium	Java	[]
136	Subarray Sum.java	Easy	Java	[]
137	Subset.java	Medium	Java	[]
138	Subsets II.java	Medium	Java	[]
139	Summary Ranges.java	Medium	Java	[]
140	The Smallest Difference.java	N/A	Java	[]
141	Top K Frequent Elements.java	Medium	Java	[]
142	Top K Frequent Words.java	Medium	Java	[]
143	Topological Sorting.java	Medium	Java	[]
144	Total Occurrence of Target.java	N/A	Java	[]
145	Trailing Zeros.java	N/A	Java	[]
146	Tweaked Identical Binary Tree.java	Easy	Java	[DFS, Tree]
147	Two Lists Sum.java	N/A	Java	[]
148	Two Strings Are Anagrams.java	Easy	Java	[]
149	Ugly Number II.java	Medium	Java	[]
150	Ugly Number.java	Medium	Java	[]
151	Unique Binary Search Tree II.java	Medium	Java	[BST]
152	Unique Characters.java	N/A	Java	[]
153	Unique Word Abbreviation.java	Medium	Java	[]
154	Valid Parentheses.java	Easy	Java	[]
155	Valid Sudoku.java	Easy	Java	[]
156	Word Break.java	Medium	Java	[]
157	Word Ladder II.java	Hard	Java	[]
158	Word Ladder.java	Medium	Java	[]
159	Word Pattern.java	Easy	Java	[]
160	Zigzag Iterator.java	Medium	Java	[BST]
161	Find Anagram Mappings.java	Easy	Java	[Hash Table]
162	Judge Route Circle.java	Easy	Java	[String]
163	Island Perimeter.java	Easy	Java	[Hash Table]
164	First Unique Character in a String.java	Easy	Java	[Hash Table, String]
165	Power of Three.java	Easy	Java	[Math]
166	Plus One.java	Easy	Java	[Array, Math]
167	Power of Two.java	Easy	Java	[Bit Manipulation, Math]
168	Reverse Vowels of a String.java	Easy	Java	[String, Two Pointers]
169	Guess Number Higher or Lower.java	Easy	Java	[Binary Search]
170	Encode and Decode TinyURL.java	Medium	Java	[Hash Table, Math]
171	Wiggle Sort.java	Medium	Java	[Array, Sort]
172	Queue Reconstruction by Height.java	Medium	Java	[Greedy]
173	2 Sum.java	Easy	Java	[Array, Hash Table]
174	2 Sum II - Input array is sorted.java	Medium	Java	[Array, Binary Search, Two Pointers]
175	2 Sum II.java	Medium	Java	[Array, Binary Search, Two Pointers]
176	Coin Change.java	Medium	Java	[DP, Memoization, Sequence DP]
177	Maximum Product Subarray.java	Medium	Java	[Array, DP]
178	3 Sum Closest.java	Medium	Java	[Array, Two Pointers]
179	Triangle Count.java	Medium	Java	[Array]
180	3 Sum.java	Medium	Java	[Array, Two Pointers]
181	4 Sum.java	Medium	Java	[Hash Table]
182	k Sum.java	Hard	Java	[DP]
183	Longest Increasing Subsequence.java	Medium	Java	[Binary Search, Coordinate DP, DP, Memoization, Sequence DP]
184	Unique Binary Search Tree.java	Medium	Java	[BST, DP, Tree]
185	Trim a Binary Search Tree.java	Easy	Java	[BST, Tree]
186	Unique Paths II.java	Medium	Java	[Array, Coordinate DP, DP]
187	Bomb Enemy.java	Medium	Java	[Coordinate DP, DP]
188	3 Sum Smaller.java	Medium	Java	[Array, Two Pointers]
189	Array Partition I.java	Easy	Java	[Array]
190	1-bit and 2-bit Characters.java	Easy	Java	[Array]
191	Non-decreasing Array.java	Easy	Java	[Array]
192	Max Consecutive Ones.java	Easy	Java	[Array]
193	Find All Numbers Disappeared in an Array.java	Easy	Java	[Array]
194	Maximum Average Subarray I.java	Easy	Java	[Array]
195	Largest Number At Least Twice of Others.java	Easy	Java	[Array]
196	Toeplitz Matrix.java	Easy	Java	[Array]
197	Sum of Two Integers.java	Easy	Java	[Bit Manipulation]
198	Swap Bits.java	Easy	Java	[Bit Manipulation]
199	Update Bits.java	Medium	Java	[Bit Manipulation]
200	Maximum XOR of Two Numbers in an Array.java	Medium	Java	[Bit Manipulation, Trie]
201	Perfect Squares.java	Medium	Java	[BFS, DP, Math, Partition DP]
202	Backpack VI.java	Medium	Java	[Backpack DP, DP]
203	Copy Books.java	Hard	Java	[Binary Search, DP, Partition DP]
204	Valid Perfect Square.java	Review	Java	[Binary Search, Math]
205	Intersection of Two Arrays II.java	Easy	Java	[Binary Search, Hash Table, Sort, Two Pointers]
206	Longest Palindromic Subsequence.java	Medium	Java	[DP, Interval DP, Memoization]
207	Scramble String.java	Hard	Java	[DP, Interval DP, String]
208	Binary Search Tree Iterator.java	Medium	Java	[BST, Design, Stack, Tree]
209	Flatten Nested List Iterator.java	Medium	Java	[Design, Stack]
210	Best Time to Buy and Sell Stock with Cooldown.java	Medium	Java	[DP]
211	Find Peak Element.java	Medium	Java	[Array, Binary Search]
212	Longest Common Subsequence.java	Medium	Java	[DP, Double Sequence DP]
213	Interleaving String.java	Hard	Java	[DP, String]
214	Letter Combinations of a Phone Number.java	Medium	Java	[Backtracking, String]
215	Edit Distance.java	Hard	Java	[DP, Double Sequence DP, String]
216	Distinct Subsequences.java	Hard	Java	[DP, String]
217	Regular Expression Matching.java	Review	Java	[Backtracking, DP, String]
218	Majority Element.java	Easy	Java	[Array, Bit Manipulation, Divide and Conquer]
219	Wildcard Matching.java	Hard	Java	[Backtracking, DP, Greedy, String]
220	Ones and Zeroes.java	Hard	Java	[DP]
221	Pow(x,n).java	Medium	Java	[Binary Search, Math]
222	Word Break II.java	Review	Java	[Backtracking, DP]
223	Nested List Weight Sum.java	Easy	Java	[DFS]
224	Same Tree.java	Easy	Java	[DFS, Tree]
225	Convert Sorted Array to Binary Search Tree.java	Easy	Java	[DFS, Tree]
226	Binary Tree Maximum Path Sum.java	Review	Java	[DFS, Tree]
227	Construct Binary Tree from Inorder and Preorder Traversal.java	Medium	Java	[Array, DFS, Tree]
228	Path Sum.java	Easy	Java	[DFS, Tree]
229	Add Binary.java	Easy	Java	[Math, String]
230	Add Digits.java	Easy	Java	[Math]
231	Add Two Numbers.java	Medium	Java	[Linked List, Math]
232	Add Two Numbers II.java	Medium	Java	[Linked List]
233	Balanced Binary Tree.java	Medium	Java	[DFS, Tree]
234	Valid Anagram.java	Easy	Java	[Hash Table, Sort]
235	Populating Next Right Pointers in Each Node.java	Medium	Java	[DFS, Tree]
236	Validate Binary Search Tree.java	Medium	Java	[BST, DFS, Tree]
237	Convert Sorted List to Binary Search Tree.java	Medium	Java	[DFS, Linked List]
238	Flatten Binary Tree to Linked List.java	Medium	Java	[Binary Tree, DFS]
239	Binary Tree Paths.java	Easy	Java	[Binary Tree, DFS]
240	Minimum Size Subarray Sum.java	Medium	Java	[Array, Binary Search, Two Pointers]
241	Clone Graph.java	Medium	Java	[BFS, DFS, Graph]
242	Longest Substring Without Repeating Characters.java	Medium	Java	[Hash Table, String, Two Pointers]
243	Minimum Window Substring.java	Hard	Java	[Hash Table, String, Two Pointers]
244	Linked List Cycle.java	Easy	Java	[Linked List, Two Pointers]
245	Remove Nth Node From End of List.java	Medium	Java	[Linked List, Two Pointers]
246	Longest Substring with At Most K Distinct Characters.java	Medium	Java	[Hash Table, String]
247	Linked List Cycle II.java	Medium	Java	[Linked List, Two Pointers]
248	Kth Smallest Number in Sorted Matrix.java	Medium	Java	[Binary Search, Heap]
249	Find Minimum in Rotated Sorted Array.java	Medium	Java	[Array, Binary Search]
250	Find Minimum in Rotated Sorted Array II.java	Hard	Java	[Array, Binary Search]
251	Connecting Graph.java	Medium	Java	[Union Find]
252	Connecting Graph II.java	Medium	Java	[Union Find]
253	Connecting Graph III.java	Medium	Java	[Union Find]
254	Number of Islands.java	Medium	Java	[BFS, DFS, Union Find]
255	Number of Islands II.java	Hard	Java	[Union Find]
256	Graph Valid Tree.java	Medium	Java	[BFS, DFS, Graph, Union Find]
257	Surrounded Regions.java	Review	Java	[BFS, DFS, Union Find]
258	Implement Trie.java	Medium	Java	[Design, Trie]
259	Add and Search Word.java	Medium	Java	[Backtracking, Design, Trie]
260	Word Search II.java	Hard	Java	[Backtracking, DFS, Trie]
261	Word Search.java	Medium	Java	[Array, Backtracking]
262	Word Squares.java	Hard	Java	[Backtracking, Trie]
263	Trapping Rain Water.java	Hard	Java	[Array, Stack, Two Pointers]
264	Trapping Rain Water II.java	Hard	Java	[BFS, Heap]
265	Data Stream Median.java	Hard	Java	[Design, Heap]
266	Sliding Window Median.java	Hard	Java	[Design, Heap]
267	Min Stack.java	Easy	Java	[Design, Stack]
268	Implement Queue using Stacks.java	Easy	Java	[Design, Stack]
269	Expression Expand.java	Medium	Java	[DFS, Divide and Conquer, Stack]
270	Largest Rectangle in Histogram.java	Hard	Java	[Array, Monotonous Stack, Stack]
271	Maximum Binary Tree.java	Medium	Java	[Stack, Tree]
272	Reverse Integer.java	Easy	Java	[Math]
273	Swap Nodes in Pairs.java	Medium	Java	[Linked List]
274	Find Peak Element II.java	Hard	Java	[Binary Search, DFS, Divide and Conquer]
275	Sqrt(x).java	Easy	Java	[Binary Search, Math]
276	First Bad Version.java	Easy	Java	[Binary Search]
277	Wood Cut.java	Medium	Java	[Binary Search]
278	Find the Duplicate Number.java	Medium	Java	[Array, Binary Search, Two Pointers]
279	Palindrome Pairs.java	Hard	Java	[Hash Table, String, Trie]
280	Game of Life.java	Medium	Java	[Array]
281	Maximum Average Subarray II.java	Review	Java	[Array, Binary Search]
282	Meeting Rooms.java	Easy	Java	[Sort, Sweep Line]
283	Number of Airplane in the sky.java	Medium	Java	[Array, Interval, Sort, Sweep Line]
284	Meeting Rooms II.java	Medium	Java	[Greedy, Heap, Sort, Sweep Line]
285	Building Outline.java	Review	Java	[Binary Indexed Tree, Divide and Conquer, Heap, Segment Tree, Sweep Line]
286	Unique Path.java	Medium	Java	[Array, Coordinate DP, DP]
287	Maximal Rectangle.java	Hard	Java	[Array, DP, Hash Table, Stack]
288	Maximal Square.java	Medium	Java	[Coordinate DP, DP]
289	Longest Increasing Path in a Matrix.java	Hard	Java	[DFS, DP, Memoization, Topological Sort]
290	Coins in a Line.java	Medium	Java	[DP, Game Theory, Greedy]
291	Coins in a Line II.java	Medium	Java	[Array, DP, Game Theory, Memoization, MiniMax]
292	Binary Tree Inorder Traversal.java	Easy	Java	[Hash Table, Stack, Tree]
293	Path Sum II.java	Easy	Java	[DFS, Tree]
294	Binary Tree Postorder Traversal.java	Medium	Java	[Stack, Tree, Two Stacks]
295	Change to Anagram.java	Easy	Java	[String]
296	Classical Binary Search.java	Easy	Java	[Binary Search]
297	Climbing Stairs.java	Easy	Java	[DP, Memoization, Sequence DP]
298	Coins in a Line III.java	Hard	Java	[Array, DP, Game Theory, Interval DP, Memoization]
299	Closest Binary Search Tree Value.java	Easy	Java	[BST, Binary Search, Tree]
300	Compare Version Numbers.java	Medium	Java	[String]
301	Count Complete Tree Nodes.java	Medium	Java	[Binary Search, Tree]
302	Course Schedule.java	Medium	Java	[BFS, DFS, Graph, Topological Sort]
303	Course Schedule II.java	Medium	Java	[BFS, DFS, Graph, Topological Sort]
304	Alien Dictionary.java	Hard	Java	[BFS, Backtracking, DFS, Graph, Topological Sort]
305	Binary Tree Preorder Traversal.java	Easy	Java	[BFS, DFS, Stack, Tree]
306	Closest Number in Sorted Array.java	Easy	Java	[Binary Search]
307	Complete Binary Tree.java	Easy	Java	[BFS, DFS, Tree]
308	Compare Strings.java	Easy	Java	[String]
309	Contains Duplicate.java	Easy	Java	[Array, Hash Table]
310	Contains Duplicate II.java	Easy	Java	[Array, Hash Table]
311	Contains Duplicate III.java	Medium	Java	[BST]
312	Burst Balloons.java	Hard	Java	[DP, Divide and Conquer, Interval DP, Memoization]
313	Nim Game.java	Easy	Java	[Brainteaser, DP, Game Theory]
314	Convert Integer A to Integer B.java	Easy	Java	[Bit Manipulation]
315	Cosine Similarity.java	Easy	Java	[Basic Implementation]
316	Count 1 in Binary.java	Easy	Java	[Bit Manipulation]
317	Count and Say.java	Easy	Java	[Basic Implementation, String]
318	One Edit Distance.java	Medium	Java	[String]
319	K Edit Distance.java	Hard	Java	[DP, Double Sequence DP, Trie]
320	Jump Game.java	Medium	Java	[Array, DP, Greedy]
321	Coin Change 2.java	Medium	Java	[DP, Sequence DP]
322	Paint House.java	Easy	Java	[DP, Sequence DP]
323	Decode Ways.java	Medium	Java	[DP, Partition DP, String]
324	Longest Continuous Increasing Subsequence.java	Easy	Java	[Array, Coordinate DP, DP]
325	Minimum Path Sum.java	Medium	Java	[Array, Coordinate DP, DP]
326	Counting Bits.java	Medium	Java	[Bit Manipulation, Bitwise DP, DP]
327	Continuous Subarray Sum.java	Medium	Java	[Coordinate DP, DP, Math]
328	House Robber.java	Easy	Java	[DP, Sequence DP]
329	House Robber II.java	Medium	Java	[DP, Sequence DP]
330	House Robber III.java	Medium	Java	[DFS, DP, Status DP, Tree]
331	Paint House II.java	Hard	Java	[DP, Sequence DP]
332	Best Time to Buy and Sell Stock I.java	Easy	Java	[Array, DP, Sequence DP]
333	Best Time to Buy and Sell Stock II.java	Easy	Java	[Array, DP, Greedy, Sequence DP]
334	Best Time to Buy and Sell Stock III .java	Hard	Java	[Array, DP, Sequence DP]
335	Best Time to Buy and Sell Stock IV.java	Hard	Java	[DP, Sequence DP]
336	Russian Doll Envelopes.java	Hard	Java	[Binary Search, Coordinate DP, DP]
337	Jump Game II.java	Hard	Java	[Array, Coordinate DP, DP, Greedy]
338	Palindrome Partitioning.java	Medium	Java	[Backtracking, DFS]
339	Permutation in String.java	Medium	Java	[Two Pointers]
340	Permutations II.java	Medium	Java	[Backtracking]
341	Shuffle an Array.java	Medium	Java	[Permutation]
342	Find All Anagrams in a String.java	Easy	Java	[Hash Table]
343	Group Anagrams.java	Medium	Java	[Hash Table, String]
344	Backpack.java	Medium	Java	[Backpack DP, DP]
345	Backpack II.java	Medium	Java	[Backpack DP, DP]
346	Backpack V.java	Medium	Java	[Backpack DP, DP]
347	Count Primes.java	Easy	Java	[Hash Table, Math]
348	Delete Node in a Linked List.java	Easy	Java	[Linked List]
349	Excel Sheet Column Number.java	Easy	Java	[Math]
350	Excel Sheet Column Title.java	Easy	Java	[Math]
351	Flip Game.java	Easy	Java	[String]
352	Flip Game II.java	Review	Java	[DFS, backtracking]
353	Expression Tree Build.java	Hard	Java	[Binary Tree, Expression Tree, Stack]
354	Expression Evaluation.java	Hard	Java	[Binary Tree, DFS, Expression Tree, Stack]
355	Convert Expression to Polish Notation.java	Hard	Java	[Binary Tree, DFS, Expression Tree, Stack]
356	Convert Expression to Reverse Polish Notation.java	Hard	Java	[Binary Tree, DFS, Expression Tree, Stack]
357	Evaluate Reverse Polish Notation.java	Medium	Java	[Stack]
358	Decode Ways II.java	Hard	Java	[DP, Partition DP]
359	Palindrome Partitioning II.java	Hard	Java	[DP, Partition DP]
360	Backpack III.java	Hard	Java	[Backpack DP, DP]
361	First Missing Positive.java	Hard	Java	[Array]
362	Gas Station.java	Medium	Java	[Greedy]
363	Implement strStr().java	Easy	Java	[String, Two Pointers]
364	Insertion Sort List.java	Medium	Java	[Linked List, Sort]
365	Integer to English Words.java	Hard	Java	[Math, String]
366	Interleaving Positive and Negative Numbers.java	Medium	Java	[Two Pointers]
367	Largest Number.java	Medium	Java	[Sort]
368	Last Position of Target.java	Easy	Java	[Binary Search]
369	Length of Last Word.java	Easy	Java	[String]
370	Longest Common Substring.java	Medium	Java	[DP, Double Sequence DP, String]
371	Longest Consecutive Sequence.java	Medium	Java	[Array, Hash Table]
372	Longest Increasing Continuous subsequence.java	Easy	Java	[Array, Coordinate DP, DP]
373	Longest Increasing Continuous subsequence II.java	Medium	Java	[Array, Coordinate DP, DP, Memoization]
374	N-Queens.java	Hard	Java	[Backtracking]
375	N-Queens II.java	Hard	Java	[Backtracking]
376	Longest Words.java	Easy	Java	[Hash Map, String]
377	Maximum Subarray.java	Easy	Java	[Array, DP, Divide and Conquer, Sequence DP]
378	Maximum Subarray II.java	Medium	Java	[Array, DP, Greedy, Sequence DP]
379	Median.java	Easy	Java	[Array, Quick Select, Quick Sort]
380	Merge Sorted Array.java	Easy	Java	[Array, Two Pointers]
381	Middle of Linked List.java	Easy	Java	[Linked List]
382	Singleton.java	Easy	Java	[Design]
383	Remove Linked List Elements.java	Easy	Java	[Linked List]
384	Fibonacci.java	Easy	Java	[DP, Math, Memoization]
385	Palindrome Linked List.java	Easy	Java	[Linked List, Two Pointers]
386	Reverse Linked List.java	Easy	Java	[Linked List]
387	Reverse Linked List II .java	Medium	Java	[Linked List]
388	Palindrome Permutation.java	Easy	Java	[Hash Table]
389	Valid Palindrome.java	Easy	Java	[String, Two Pointers]
390	Implement Stack using Queues.java	Easy	Java	[Design, Stack]
391	Implement Stack.java	Easy	Java	[Stack]
392	Invert Binary Tree.java	Easy	Java	[BFS, DFS, Tree]
393	Maximum Depth of Binary Tree.java	Easy	Java	[DFS, Tree]
394	Minimum Depth of Binary Tree.java	Easy	Java	[BFS, DFS, Tree]
395	Symmetric Tree.java	Easy	Java	[BFS, DFS, Tree]
396	Merge Two Binary Trees.java	Easy	Java	[DFS, Tree]
397	Subtree.java	Easy	Java	[DFS, Tree]
398	Lowest Common Ancestor of a Binary Tree.java	Medium	Java	[DFS, Tree]
399	Lowest Common Ancestor II.java	Easy	Java	[Hash Table, Tree]
400	Lowest Common Ancestor of a Binary Search Tree.java	Medium	Java	[BST, DFS, Tree]
401	Merge Intervals.java	Medium	Java	[Array, Sort, Sweep Line]
402	Hash Function.java	Easy	Java	[Hash Table]
403	Merge Two Sorted Lists.java	Easy	Java	[Linked List]