penn-xy/leetcode

LeetCode Problems' Solutions

LeetCode

###LeetCode Algorithm

(Notes: "♥" means you need to buy a book from Leetcode)

#	Title	Solution	Difficulty
477	Total Hamming Distance	C++	Medium
415	Add Strings	C++	Easy
414	Third Maximum Number	C++	Easy
413	Arithmetic Slices	C++	Medium
412	Fizz Buzz	C++	Easy
410	Split Array Largest Sum	C++	Hard
409	Longest Palindrome	C++	Easy
406	Queue Reconstruction by Height	C++	Medium
405	Convert a Number to Hexadecimal	C++	Easy
404	Sum of Left Leaves	C++	Easy
403	Frog Jump	C++	Hard
402	Remove K Digits	C++	Medium
401	Binary Watch	C++	Easy
400	Nth Digit	C++	Easy
399	Evaluate Division	C++	Medium
398	Random Pick Index	C++	Medium
397	Integer Replacement	C++	Medium
396	Rotate Function	C++	Easy
395	Longest Substring with At Least K Repeating Characters	C++	Medium
394	Decode String	C++	Medium
393	UTF-8 Validation	C++	Medium
392	Is Subsequence	C++	Medium
391	Perfect Rectangle	C++	Hard
390	Elimination Game	C++	Medium
389	Find the Difference	C++	Easy
388	Longest Absolute File Path	C++	Medium
387	First Unique Character in a String	C++	Easy
386	Lexicographical Numbers	C++	Medium
385	Mini Parser	C++	Medium
384	Shuffle an Array	C++	Medium
383	Ransom Note	C++	Easy
382	Linked List Random Node	C++	Medium
381	Insert Delete GetRandom O(1) - Duplicates allowed	C++	Hard
380	Insert Delete GetRandom O(1)	C++	Hard
377	Combination Sum IV	C++	Medium
376	Wiggle Subsequence	C++	Medium
350	Intersection of Two Arrays II	C++	Easy
349	Intersection of Two Arrays	C++	Easy
347	Top K Frequent Elements	C++	Medium
345	Reverse Vowels of a String	C++	Easy
344	Reverse String	C++	Easy
343	Integer Break	C++	Medium
342	Power of Four	C++	Easy
341	Flatten Nested List Iterator	C++	Medium
338	Counting Bits	C++	Medium
337	House Robber III	C++	Medium
336	Palindrome Pairs	C++	Hard
334	Increasing Triplet Subsequence	C++	Medium
332	Reconstruct Itinerary	C++	Medium
331	Verify Preorder Serialization of a Binary Tree	C++	Medium
330	Patching Array	C++	Medium
329	Longest Increasing Path in a Matrix	C++	Medium
328	Odd Even Linked List	C++	Easy
327	Count of Range Sum	C++	Hard
326	Power of Three	C++	Easy
324	Wiggle Sort II	C++	Medium
322	Coin Change	C++	Medium
321	Create Maximum Number	C++	Hard
319	Bulb Switcher	C++	Medium
318	Maximum Product of Word Lengths	C++	Medium
316	Remove Duplicate Letters	C++	Hard
315	Count of Smaller Numbers After Self	C++	Hard
313	Super Ugly Number	C++	Medium
312	Burst Balloons	C++	Hard
310	Minimum Height Trees	C++	Medium
307	Range Sum Query - Mutable	C++	Medium
306	Additive Number	C++	Medium
304	Range Sum Query 2D - Immutable	C++	Medium
303	Range Sum Query - Immutable	C++	Easy
301	Remove Invalid Parentheses	C++	Hard
300	Longest Increasing Subsequence	C++	Medium
299	Bulls and Cows	C++	Easy
297	Serialize and Deserialize Binary Tree	C++	Medium
295	Find Median from Data Stream	C++	Hard
292	Nim Game	C++	Easy
290	Word Pattern	C++	Easy
287	Find the Duplicate Number	C++	Hard
285	Inorder Successor in BST ♥	Java	Medium
284	Peeking Iterator	C++	Medium
283	Move Zeroes	C++	Easy
282	Expression Add Operators	C++	Hard
279	Perfect Squares	C++	Medium
278	First Bad Version	C++, Java	Easy
275	H-Index II	C++	Medium
274	H-Index	C++	Medium
273	Integer to English Words	C++	Medium
268	Missing Number	C++	Medium
264	Ugly Number II	C++	Medium
263	Ugly Number	C++	Easy
260	Single Number III	C++	Medium
258	Add Digits	C++	Easy
257	Binary Tree Paths	C++	Easy
242	Valid Anagram	C++	Easy
241	Different Ways to Add Parentheses	C++	Medium
240	Search a 2D Matrix II	C++	Medium
239	Sliding Window Maximum	C++	Hard
238	Product of Array Except Self	C++	Medium
237	Delete Node in a Linked List	C++	Easy
236	Lowest Common Ancestor of a Binary Tree	C++, Java	Medium
235	Lowest Common Ancestor of a Binary Search Tree	C++	Easy
234	Palindrome Linked List	C++	Easy
233	Number of Digit One	C++	Medium
232	Implement Queue using Stacks	C++	Easy
231	Power of Two	C++	Easy
230	Kth Smallest Element in a BST	C++	Medium
229	Majority Element II	C++	Medium
228	Summary Ranges	C++	Easy
227	Basic Calculator II	C++	Medium
226	Invert Binary Tree	C++	Easy
225	Implement Stack using Queues	C++	Medium
224	Basic Calculator	C++	Medium
223	Rectangle Area	C++	Easy
222	Count Complete Tree Nodes	C++	Medium
221	Maximal Square	C++	Medium
220	Contains Duplicate III	C++	Medium
219	Contains Duplicate II	C++	Easy
218	The Skyline Problem	C++	Hard
217	Contains Duplicate	C++	Easy
216	Combination Sum III	C++	Medium
215	Kth Largest Element in an Array	C++	Medium
214	Shortest Palindrome	C++	Hard
213	House Robber II	C++	Medium
212	Word Search II	C++	Hard
211	Add and Search Word - Data structure design	C++	Medium
210	Course Schedule II	C++	Medium
209	Minimum Size Subarray Sum	C++	Medium
208	Implement Trie (Prefix Tree)	C++	Medium
207	Course Schedule	C++	Medium
206	Reverse Linked List	C++	Easy
205	Isomorphic Strings	C++	Easy
204	Count Primes	C++	Easy
203	Remove Linked List Elements	C++	Easy
202	Happy Number	C++	Easy
201	Bitwise AND of Numbers Range	C++	Medium
200	Number of Islands	C++	Medium
199	Binary Tree Right Side View	C++	Medium
198	House Robber	C++	Easy
191	Number of 1 Bits	C++	Easy
190	Reverse Bits	C++	Easy
189	Rotate Array	C++	Easy
188	Best Time to Buy and Sell Stock IV	C++	Hard
187	Repeated DNA Sequences	C++	Medium
186	Reverse Words in a String II ♥	C++	Medium
179	Largest Number	C++	Medium
174	Dungeon Game	C++	Hard
173	Binary Search Tree Iterator	C++, Java	Medium
172	Factorial Trailing Zeroes	C++	Easy
171	Excel Sheet Column Number	C++	Easy
170	Two Sum III - Data structure design ♥	C++	Easy
169	Majority Element	C++	Easy
168	Excel Sheet Column Title	C++	Easy
167	Two Sum II - Input array is sorted ♥	C++	Medium
166	Fraction to Recurring Decimal	C++	Medium
165	Compare Version Numbers	C++	Easy
164	Maximum Gap	C++	Hard
163	Missing Ranges ♥	C++	Medium
162	Find Peak Element	C++, Java	Medium
161	One Edit Distance♥	C++	Medium
160	Intersection of Two Linked Lists	C++	Easy
159	Longest Substring with At Most Two Distinct Characters ♥	C++	Hard
158	Read N Characters Given Read4 II - Call multiple times ♥	C++	Hard
157	Read N Characters Given Read4 ♥	C++	Easy
156	Binary Tree Upside Down ♥	C++	Medium
155	Min Stack	C++	Easy
154	Find Minimum in Rotated Sorted Array II	C++	Hard
153	Find Minimum in Rotated Sorted Array	C++, Java	Medium
152	Maximum Product Subarray	C++	Medium
151	Reverse Words in a String	C++	Medium
150	Evaluate Reverse Polish Notation	C++	Medium
149	Max Points on a Line	C++	Hard
148	Sort List	C++	Medium
147	Insertion Sort List	C++	Medium
146	LRU Cache	C++, Java	Hard
145	Binary Tree Postorder Traversal	C++	Hard
144	Binary Tree Preorder Traversal	C++, Java	Medium
143	Reorder List	C++	Medium
142	Linked List Cycle II	C++	Medium
141	Linked List Cycle	C++	Medium
140	Word Break II	C++	Hard
139	Word Break	C++	Medium
138	Copy List with Random Pointer	C++	Hard
137	Single Number II	C++	Medium
136	Single Number	C++	Medium
135	Candy	C++	Hard
134	Gas Station	C++	Medium
133	Clone Graph	C++	Medium
132	Palindrome Partitioning II	C++	Hard
131	Palindrome Partitioning	C++	Medium
130	Surrounded Regions	C++	Medium
129	Sum Root to Leaf Numbers	C++	Medium
128	Longest Consecutive Sequence	C++	Hard
127	Word Ladder	C++	Medium
126	Word Ladder II	C++	Hard
125	Valid Palindrome	C++	Easy
124	Binary Tree Maximum Path Sum	C++, Java	Hard
123	Best Time to Buy and Sell Stock III	C++	Hard
122	Best Time to Buy and Sell Stock II	C++	Medium
121	Best Time to Buy and Sell Stock	C++	Medium
120	Triangle	C++, Java	Medium
119	Pascal's Triangle II	C++	Easy
118	Pascal's Triangle	C++	Easy
117	Populating Next Right Pointers in Each Node II	C++	Hard
116	Populating Next Right Pointers in Each Node	C++	Medium
115	Distinct Subsequences	C++	Hard
114	Flatten Binary Tree to Linked List	C++	Medium
113	Path Sum II	C++	Medium
112	Path Sum	C++	Easy
111	Minimum Depth of Binary Tree	C++	Easy
110	Balanced Binary Tree	C++, Java	Easy
109	Convert Sorted List to Binary Search Tree	C++	Medium
108	Convert Sorted Array to Binary Search Tree	C++	Medium
107	Binary Tree Level Order Traversal II	C++	Easy
106	Construct Binary Tree from Inorder and Postorder Traversal	C++	Medium
105	Construct Binary Tree from Preorder and Inorder Traversal	C++	Medium
104	Maximum Depth of Binary Tree	C++, Java	Easy
103	Binary Tree Zigzag Level Order Traversal	C++	Medium
102	Binary Tree Level Order Traversal	C++, Java	Easy
101	Symmetric Tree	C++	Easy
100	Same Tree	C++	Easy
99	Recover Binary Search Tree	C++	Hard
98	Validate Binary Search Tree	C++, Java	Medium
97	Interleaving String	C++	Hard
96	Unique Binary Search Trees	C++	Medium
95	Unique Binary Search Trees II	C++	Medium
94	Binary Tree Inorder Traversal	C++	Medium
93	Restore IP Addresses	C++	Medium
92	Reverse Linked List II	C++	Medium
91	Decode Ways	C++	Medium
90	Subsets II	C++, Java	Medium
89	Gray Code	C++	Medium
88	Merge Sorted Array	C++	Easy
87	Scramble String	C++	Hard
86	Partition List	C++	Medium
85	Maximal Rectangle	C++	Hard
84	Largest Rectangle in Histogram	C++	Hard
83	Remove Duplicates from Sorted List	C++	Easy
82	Remove Duplicates from Sorted List II	C++	Medium
81	Search in Rotated Sorted Array II	C++	Medium
80	Remove Duplicates from Sorted Array II	C++	Medium
79	Word Search	C++	Medium
78	Subsets	C++, Java	Medium
77	Combinations	C++	Medium
76	Minimum Window Substring	C++	Hard
75	Sort Colors	C++	Medium
74	Search a 2D Matrix	C++, Java	Medium
73	Set Matrix Zeroes	C++	Medium
72	Edit Distance	C++	Hard
71	Simplify Path	C++	Medium
70	Climbing Stairs	C++, Java	Easy
69	Sqrt(x)	C++	Medium
68	Text Justification	C++	Hard
67	Add Binary	C++	Easy
66	Plus One	C++	Easy
65	Valid Number	C++	Easy
64	Minimum Path Sum	C++, Java	Medium
63	Unique Paths II	C++, Java	Medium
62	Unique Paths	C++, Java	Medium
61	Rotate List	C++	Medium
60	Permutation Sequence	C++	Medium
59	Spiral Matrix II	C++	Medium
58	Length of Last Word	C++	Easy
57	Insert Interval	C++	Hard
56	Merge Intervals	C++	Hard
55	Jump Game	C++	Medium
54	Spiral Matrix	C++	Medium
53	Maximum Subarray	C++	Medium
52	N-Queens II	C++	Hard
51	N-Queens	C++	Hard
50	"Pow(x, n)"	C++	Medium
49	Group Anagrams	C++	Medium
48	Rotate Image	C++	Medium
47	Permutations II	C++	Hard
46	Permutations	C++	Medium
45	Jump Game II	C++	Hard
44	Wildcard Matching	C++	Hard
43	Multiply Strings	C++	Medium
42	Trapping Rain Water	C++	Hard
41	First Missing Positive	C++	Hard
40	Combination Sum II	C++	Medium
39	Combination Sum	C++	Medium
38	Count and Say	C++	Easy
37	Sudoku Solver	C++	Hard
36	Valid Sudoku	C++	Easy
35	Search Insert Position	C++, Java	Medium
34	Search for a Range	C++, Java	Medium
33	Search in Rotated Sorted Array	C++, Java	Hard
32	Longest Valid Parentheses	C++	Hard
31	Next Permutation	C++	Medium
30	Substring with Concatenation of All Words	C++	Hard
29	Divide Two Integers	C++	Medium
28	Implement strStr()	C++, Java	Easy
27	Remove Element	C++	Easy
26	Remove Duplicates from Sorted Array	C++	Easy
25	Reverse Nodes in k-Group	C++	Hard
24	Swap Nodes in Pairs	C++	Medium
23	Merge k Sorted Lists	C++	Hard
22	Generate Parentheses	C++	Medium
21	Merge Two Sorted Lists	C++	Easy
20	Valid Parentheses	C++	Easy
19	Remove Nth Node From End of List	C++	Easy
18	4Sum	C++	Medium
17	Letter Combinations of a Phone Number	C++	Medium
16	3Sum Closest	C++	Medium
15	3Sum	C++	Medium
14	Longest Common Prefix	C++	Easy
13	Roman to Integer	C++	Easy
12	Integer to Roman	C++	Medium
11	Container With Most Water	C++	Medium
10	Regular Expression Matching	C++	Hard
9	Palindrome Number	C++	Easy
8	String to Integer (atoi)	C++	Easy
7	Reverse Integer	C++	Easy
6	ZigZag Conversion	C++	Easy
5	Longest Palindromic Substring	C++	Medium
4	Median of Two Sorted Arrays	C++	Hard
3	Longest Substring Without Repeating Characters	C++	Medium
2	Add Two Numbers	C++	Medium
1	Two Sum	C++	Medium

###LeetCode Shell

#	Title	Solution	Difficulty
4	Tenth Line	Bash	Easy
3	Transpose File	Bash	Medium
2	Valid Phone Numbers	Bash	Easy
1	Word Frequency	Bash	Medium

###LintCode

#	Title	Solution	Difficulty
1	Search in a big sorted array	Java	Medium
2	Search Range in Binary Search Tree	Java	Medium