摘要：Pow(x, n)Implement pow(x,n).算法思路：二分法，没什么好说的，小心点就行；这个题时间比较苛刻。return pow(x,n >> 1) * pow(x,n >> 1) 是过不去的，因此把pow(x,n / 2)求出来先。其实时间复杂度而言，是一样的。【注意】：n的取值范围；... 阅读全文

摘要：Subsets IIGiven a collection of integers that might contain duplicates,S, return all possible subsets.Note:Elements in a subset must be in non-descend... 阅读全文

摘要：SubsetsGiven a set of distinct integers,S, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must... 阅读全文

摘要：Insert IntervalGiven a set ofnon-overlappingintervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals... 阅读全文

摘要：Merge IntervalsGiven a collection of intervals, merge all overlapping intervals.For example,Given[1,3],[2,6],[8,10],[15,18],return[1,6],[8,10],[15,18]... 阅读全文

摘要：Valid PalindromeGiven a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a pla... 阅读全文

摘要：Merge Sorted ArrayGiven two sorted integer arrays A and B, merge B into A as one sorted array.Note:You may assume that A has enough space (size that i... 阅读全文

摘要：Length of Last WordGiven a stringsconsists of upper/lower-case alphabets and empty space characters' ', return the length of last word in the string.I... 阅读全文

摘要：Simplify PathGiven an absolute path for a file (Unix-style), simplify it.For example,path="/home/", =>"/home"path="/a/./b/../../c/", =>"/c"click to sh... 阅读全文

摘要：Add BinaryGiven two binary strings, return their sum (also a binary string).For example,a ="11"b ="1"Return"100".算法思路：模拟二进制加法，跟十进制木有区别，将a，b转置(不转置的话，倒着... 阅读全文

摘要：Substring with Concatenation of All WordsYou are given a string,S, and a list of words,L, that are all of the same length. Find all starting indices o... 阅读全文

摘要：Valid ParenthesesGiven a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must clos... 阅读全文

摘要：Reverse Words in a StringGiven an input string, reverse the string word by word.For example,Given s = "the sky is blue",return "blue is sky the".click... 阅读全文

摘要：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 i... 阅读全文

摘要：Gray CodeThe gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integernrepresenting the tot... 阅读全文

摘要：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 fo... 阅读全文

摘要：Next PermutationImplement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangemen... 阅读全文

摘要：Permutations IIGiven a collection of numbers that might contain duplicates, return all possible unique permutations.For example,[1,1,2]have the follow... 阅读全文

摘要：Add Two NumbersYou are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes co... 阅读全文

摘要：CombinationsGiven two integersnandk, return all possible combinations ofknumbers out of 1 ...n.For example,Ifn= 4 andk= 2, a solution is:[ [2,4], [3... 阅读全文