过题目，中等难度的

	8	String to Integer (atoi)		13.9%	Medium
	151	Reverse Words in a String		15.7%	Medium
	288	Unique Word Abbreviation		15.8%	Medium
	29	Divide Two Integers		16.0%	Medium
	166	Fraction to Recurring Decimal		17.0%	Medium
	130	Surrounded Regions		17.8%	Medium
	91	Decode Ways		19.1%	Medium
	307	Range Sum Query - Mutable		19.1%	Medium
	127	Word Ladder		19.2%	Medium
	220	Contains Duplicate III		19.3%	Medium
	165	Compare Version Numbers		19.5%	Medium
	444	Sequence Reconstruction		19.7%	Medium
	468	Validate IP Address		20.3%	Medium
	523	Continuous Subarray Sum		20.7%	Medium
	211	Add and Search Word - Data structure design		20.9%	Medium
	15	3Sum		21.3%	Medium
	179	Largest Number		21.8%	Medium
	98	Validate Binary Search Tree		22.6%	Medium
	464	Can I Win		23.4%	Medium
	304	Range Sum Query 2D - Immutable		23.4%	Medium
	3	Longest Substring Without Repeating Characters		23.9%	Medium
	61	Rotate List		24.1%	Medium
	71	Simplify Path		24.4%	Medium
	152	Maximum Product Subarray		24.8%	Medium
	143	Reorder List		24.9%	Medium
	5	Longest Palindromic Substring		24.9%	Medium
	54	Spiral Matrix		25.0%	Medium
	355	Design Twitter		25.0%	Medium
	133	Clone Graph		25.0%	Medium
	324	Wiggle Sort II		25.4%	Medium
	79	Word Search		25.7%	Medium
	353	Design Snake Game		25.9%	Medium
	18	4Sum		26.0%	Medium
	163	Missing Ranges		26.0%	Medium
	402	Remove K Digits		26.1%	Medium
	322	Coin Change		26.1%	Medium
	6	ZigZag Conversion		26.2%	Medium
	93	Restore IP Addresses		26.2%	Medium
	43	Multiply Strings		26.3%	Medium
	150	Evaluate Reverse Polish Notation		26.3%	Medium
	271	Encode and Decode Strings		26.3%	Medium
	210	Course Schedule II		26.3%	Medium
	208	Implement Trie (Prefix Tree)		26.4%	Medium
	365	Water and Jug Problem		26.5%	Medium
	138	Copy List with Random Pointer		26.6%	Medium
	2	Add Two Numbers		26.8%	Medium
	50	Pow(x, n)		26.8%	Medium
	222	Count Complete Tree Nodes		27.1%	Medium
	306	Additive Number		27.3%	Medium
	418	Sentence Screen Fitting		27.4%	Medium
	60	Permutation Sequence		27.5%	Medium
	221	Maximal Square		27.7%	Medium
	148	Sort List		27.7%	Medium
	186	Reverse Words in a String II		27.9%	Medium
	456	132 Pattern		28.0%	Medium
	229	Majority Element II		28.0%	Medium
	332	Reconstruct Itinerary		28.3%	Medium
	31	Next Permutation		28.3%	Medium
	227	Basic Calculator II		28.4%	Medium
	310	Minimum Height Trees		28.6%	Medium
	228	Summary Ranges		28.6%	Medium
	139	Word Break		28.8%	Medium
	134	Gas Station		28.8%	Medium
	82	Remove Duplicates from Sorted List II		28.8%	Medium
	56	Merge Intervals		28.9%	Medium
	55	Jump Game		29.3%	Medium
	209	Minimum Size Subarray Sum		29.3%	Medium
	236	Lowest Common Ancestor of a Binary Tree		29.5%	Medium
	397	Integer Replacement		29.5%	Medium
	469	Convex Polygon		29.8%	Medium
	333	Largest BST Subtree		30.0%	Medium
	92	Reverse Linked List II		30.0%	Medium
	385	Mini Parser		30.1%	Medium
	187	Repeated DNA Sequences		30.2%	Medium
	373	Find K Pairs with Smallest Sums		30.2%	Medium
	356	Line Reflection		30.3%	Medium
	16	3Sum Closest		30.7%	Medium
	95	Unique Binary Search Trees II		30.8%	Medium
	161	One Edit Distance		30.8%	Medium
	379	Design Phone Directory		30.8%	Medium
	207	Course Schedule		30.9%	Medium
	396	Rotate Function		30.9%	Medium
	34	Search for a Range		31.0%	Medium
	142	Linked List Cycle II		31.0%	Medium
	105	Construct Binary Tree from Preorder and Inorder Traversal		31.1%	Medium
	63	Unique Paths II		31.1%	Medium
	467	Unique Substrings in Wraparound String		31.2%	Medium
	106	Construct Binary Tree from Inorder and Postorder Traversal		31.2%	Medium
	131	Palindrome Partitioning		31.5%	Medium
	47	Permutations II		31.5%	Medium
	267	Palindrome Permutation II		31.5%	Medium
	86	Partition List		31.8%	Medium
	264	Ugly Number II		31.8%	Medium
	40	Combination Sum II		32.0%	Medium
	113	Path Sum II		32.1%	Medium
	33	Search in Rotated Sorted Array		32.1%	Medium
	147	Insertion Sort List		32.1%	Medium
	223	Rectangle Area		32.2%	Medium
	525	Contiguous Array		32.4%	Medium
	19	Remove Nth Node From End of List		32.5%	Medium
	274	H-Index		32.5%	Medium
	49	Group Anagrams		32.7%	Medium
	120	Triangle		32.8%	Medium
	417	Pacific Atlantic Water Flow		32.9%	Medium
	81	Search in Rotated Sorted Array II		32.9%	Medium
	103	Binary Tree Zigzag Level Order Traversal		32.9%	Medium
	200	Number of Islands		33.0%	Medium
	109	Convert Sorted List to Binary Search Tree		33.1%	Medium
	17	Letter Combinations of a Phone Number		33.1%	Medium
	213	House Robber II		33.3%	Medium
	201	Bitwise AND of Numbers Range		33.3%	Medium
	368	Largest Divisible Subset		33.5%	Medium
	372	Super Pow		33.5%	Medium
	117	Populating Next Right Pointers in Each Node II		33.6%	Medium
	299	Bulls and Cows		33.7%	Medium
	275	H-Index II		33.8%	Medium
	114	Flatten Binary Tree to Linked List		34.0%	Medium
	473	Matchsticks to Square		34.0%	Medium
	36	Valid Sudoku		34.4%	Medium
	90	Subsets II		34.6%	Medium
	376	Wiggle Subsequence		34.9%	Medium
	393	UTF-8 Validation		34.9%	Medium
	505	The Maze II		34.9%	Medium
	80	Remove Duplicates from Sorted Array II		35.2%	Medium
	284	Peeking Iterator		35.2%	Medium
	450	Delete Node in a BST		35.3%	Medium
	74	Search a 2D Matrix		35.4%	Medium
	73	Set Matrix Zeroes		35.4%	Medium
	375	Guess Number Higher or Lower II		35.5%	Medium
	331	Verify Preorder Serialization of a Binary Tree		35.5%	Medium
	277	Find the Celebrity		35.5%	Medium
	388	Longest Absolute File Path		35.5%	Medium
	395	Longest Substring with At Least K Repeating Characters		35.5%	Medium
	129	Sum Root to Leaf Numbers		35.5%	Medium
	244	Shortest Word Distance II		35.6%	Medium
	279	Perfect Squares		35.6%	Medium
	314	Binary Tree Vertical Order Traversal		36.0%	Medium
	285	Inorder Successor in BST		36.2%	Medium
	11	Container With Most Water		36.2%	Medium
	162	Find Peak Element		36.3%	Medium
	289	Game of Life		36.4%	Medium
	39	Combination Sum		36.6%	Medium
	116	Populating Next Right Pointers in Each Node		36.9%	Medium
	75	Sort Colors		37.0%	Medium
	261	Graph Valid Tree		37.0%	Medium
	474	Ones and Zeroes		37.1%	Medium
	313	Super Ugly Number		37.2%	Medium
	24	Swap Nodes in Pairs		37.4%	Medium
	64	Minimum Path Sum		37.5%	Medium
	48	Rotate Image		37.6%	Medium
	533	Lonely Pixel II   New		37.6%	Medium
	300	Longest Increasing Subsequence		37.6%	Medium
	102	Binary Tree Level Order Traversal		37.8%	Medium
	78	Subsets		37.8%	Medium
	240	Search a 2D Matrix II		37.9%	Medium
	215	Kth Largest Element in an Array		38.1%	Medium
	334	Increasing Triplet Subsequence		38.2%	Medium
	416	Partition Equal Subset Sum		38.3%	Medium
	77	Combinations		38.3%	Medium
	361	Bomb Enemy		38.3%	Medium
	59	Spiral Matrix II		38.4%	Medium
	253	Meeting Rooms II		38.6%	Medium
	247	Strobogrammatic Number II		38.8%	Medium
	380	Insert Delete GetRandom O(1)		38.8%	Medium
	491	Increasing Subsequences		38.9%	Medium
	153	Find Minimum in Rotated Sorted Array		39.0%	Medium
	255	Verify Preorder Sequence in Binary Search Tree		39.3%	Medium
	199	Binary Tree Right Side View		39.4%	Medium
	251	Flatten 2D Vector		39.5%	Medium
	390	Elimination Game		39.6%	Medium
	62	Unique Paths		39.7%	Medium
	524	Longest Word in Dictionary through Deleting		39.8%	Medium
	341	Flatten Nested List Iterator		39.8%	Medium
	173	Binary Search Tree Iterator		39.8%	Medium
	249	Group Shifted Strings		39.9%	Medium
	89	Gray Code		39.9%	Medium
	309	Best Time to Buy and Sell Stock with Cooldown		40.0%	Medium
	435	Non-overlapping Intervals		40.1%	Medium
	96	Unique Binary Search Trees		40.1%	Medium
	399	Evaluate Division		40.1%	Medium
	386	Lexicographical Numbers		40.1%	Medium
	298	Binary Tree Longest Consecutive Sequence		40.3%	Medium
	137	Single Number II		40.5%	Medium
	394	Decode String		40.7%	Medium
	250	Count Univalue Subtrees		40.9%	Medium
	424	Longest Repeating Character Replacement		40.9%	Medium
	259	3Sum Smaller		41.0%	Medium
	436	Find Right Interval		41.2%	Medium
	398	Random Pick Index		41.2%	Medium
	254	Factor Combinations		41.3%	Medium
	482	License Key Formatting		41.4%	Medium
	46	Permutations		41.4%	Medium
	449	Serialize and Deserialize BST		41.5%	Medium
	377	Combination Sum IV		41.6%	Medium
	490	The Maze		41.8%	Medium
	516	Longest Palindromic Subsequence		41.9%	Medium
	325	Maximum Size Subarray Sum Equals k		41.9%	Medium
	241	Different Ways to Add Parentheses		42.0%	Medium
	319	Bulb Switcher		42.0%	Medium
	337	House Robber III		42.1%	Medium
	287	Find the Duplicate Number		42.3%	Medium
	328	Odd Even Linked List		42.4%	Medium
	452	Minimum Number of Arrows to Burst Balloons		42.5%	Medium
	230	Kth Smallest Element in a BST		42.6%	Medium
	22	Generate Parentheses		42.7%	Medium
	318	Maximum Product of Word Lengths		42.8%	Medium
	216	Combination Sum III		42.9%	Medium
	423	Reconstruct Original Digits from English		43.0%	Medium
	351	Android Unlock Patterns		43.1%	Medium
	286	Walls and Gates		43.1%	Medium
	156	Binary Tree Upside Down		43.3%	Medium
	12	Integer to Roman		43.4%	Medium
	360	Sort Transformed Array		43.4%	Medium
	378	Kth Smallest Element in a Sorted Matrix		43.6%	Medium
	487	Max Consecutive Ones II		43.6%	Medium
	144	Binary Tree Preorder Traversal		43.6%	Medium
	421	Maximum XOR of Two Numbers in an Array		44.0%	Medium
	486	Predict the Winner		44.0%	Medium
	320	Generalized Abbreviation		44.1%	Medium
	392	Is Subsequence		44.2%	Medium
	494	Target Sum		44.3%	Medium
	94	Binary Tree Inorder Traversal		44.6%	Medium
	454	4Sum II		44.9%	Medium
	343	Integer Break		45.2%	Medium
	357	Count Numbers with Unique Digits		45.4%	Medium
	384	Shuffle an Array		45.4%	Medium
	348	Design Tic-Tac-Toe		45.6%	Medium
	481	Magical String		45.7%	Medium
	294	Flip Game II		45.7%	Medium
	477	Total Hamming Distance		45.9%	Medium
	445	Add Two Numbers II		46.0%	Medium
	503	Next Greater Element II		46.3%	Medium
	382	Linked List Random Node		46.3%	Medium
	498	Diagonal Traverse		46.3%	Medium
	347	Top K Frequent Elements		46.7%	Medium
	323	Number of Connected Components in an Undirected Graph		47.2%	Medium
	238	Product of Array Except Self		47.8%	Medium
	531	Lonely Pixel I   New		48.3%	Medium
	281	Zigzag Iterator		49.2%	Medium
	245	Shortest Word Distance III		49.6%	Medium
	439	Ternary Expression Parser		49.9%	Medium
	260	Single Number III		49.9%	Medium
	451	Sort Characters By Frequency		50.2%	Medium
	311	Sparse Matrix Multiplication		50.7%	Medium
	364	Nested List Weight Sum II		50.8%	Medium
	462	Minimum Moves to Equal Array Elements II		51.1%	Medium
	484	Find Permutation		51.5%	Medium
	495	Teemo Attacking		51.6%	Medium
	529	Minesweeper		51.6%	Medium
	526	Beautiful Arrangement		51.6%	Medium
	508	Most Frequent Subtree Sum		51.9%	Medium
	442	Find All Duplicates in an Array		52.2%	Medium
	515	Find Largest Value in Each Tree Row		52.8%	Medium
	362	Design Hit Counter		53.2%	Medium
	369	Plus One Linked List		53.6%	Medium
	370	Range Addition		54.5%	Medium
	413	Arithmetic Slices		54.7%	Medium
	406	Queue Reconstruction by Height		54.7%	Medium
	513	Find Bottom Left Tree Value		55.8%	Medium
	280	Wiggle Sort		55.8%	Medium
	366	Find Leaves of Binary Tree		58.0%	Medium
	338	Counting Bits		60.0%	Medium
	419	Battleships in a Board		60.5%	Medium
	535	Encode and Decode TinyURL   New		76.6%	Medium

第8题，str to int.

单独弄了一个博文：

http://www.cnblogs.com/charlesblc/p/6517298.html