CodeAsWind

Generate ParenthesesGiven n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is: "((()))", "(()())",

Integer to Roman

Palindrome Number

Longest Palindromic SubstringGiven a string S, find the longest palindromic substring in S. You may assume that the maximum length ofS is 1000, and there exists one unique longest palindromic

Longest Substring Without Repeating CharactersGiven a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters

ZigZag ConversionThe string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P

Search in Rotated Sorted ArraySuppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become4 5 6 7 0 1 2).You are given a target value to sear

Remove Duplicates from Sorted Array IIFollow up for "Remove Duplicates":What if duplicates are allowed at most twice?For example,Given sorted array A = [1,1,1,2,2,3],Your function shou

Search in Rotated Sorted Array II

Median of Two Sorted ArraysThere are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). 

Permutation SequenceThe set [1,2,3,…,n] contains a total ofn! unique permutations.By listing and labeling all of the permutations in order,We get the following sequence (ie, for n = 3):

Two Sum Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers such that they add up to the tar

Remove Duplicates from Sorted ArrayGiven a sorted array, remove the duplicates in place such that each element appear onlyonce and return the new length.Do not allocate extra space for another a

Longest Consecutive SequenceGiven an unsorted array of integers, find the length of the longest consecutive elements sequence.For example,Given [100, 4, 200, 1, 3, 2],The longest conse

Remove ElementGiven an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't matter what you leave beyond

Next PermutationImplement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangement is not possible, it must rearrange it

Valid Sudoku

Roman to IntegerGiven a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.

Reverse IntegerReverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321

Valid ParenthesesGiven a string containing just the characters '(', ')','{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the correct order, "()" and "

3SumGiven an array S of n integers, are there elements a,b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.

Remove Element

Implement strStr()

Letter Combinations of a Phone NumberGiven a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone butto

Remove Duplicates from Sorted Array

Swap Nodes in Pairs

3Sum ClosestGiven an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input

Merge k Sorted Lists

Given an array S of n integers, are there elements a,b, c, and d in S such that a + b +c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note:Elements

Reverse Nodes in k-Group

Remove Nth Node From End of ListGiven a linked list, remove the nth node from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After removing

Container With Most WaterGiven n non-negative integers a1, a2, ...,an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of linei

Regular Expression Matching

Longest Common PrefixWrite a function to find the longest common prefix string amongst an array of strings.

String to Integer (atoi)

Trapping Rain Water题目大意