AnagramsGiven an array of strings, return all groups of strings that are anagrams.Note: All inputs will be in lower-case.善用STL，好处有两个：简单，可靠！介绍两个APIstring::compareint compare ( con

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 wo

Add BinaryGiven two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".虽然写得很长，但是代码清楚，而且一遍就过了，这就是王道！class Solution {public: string

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 contain a single digit. Add the two numbers 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.Note:Elements in a triplet (a

Decode WaysA message containing letters from A-Z is being encoded to numbers using the following mapping:'A' -> 1'B' -> 2...'Z' -> 26Given an encoded message containing digits, determine t

Divide Two IntegersDivide two integers without using multiplication, division and mod operator.考虑数据类型的限制，处理溢出的情况。class Solution {public: int divide(int dividend, int divisor) {

Wildcard MatchingImplement wildcard pattern matching with support for '?' and '*'.'?' Matches any single character.'*' Matches any sequence of characters (including the empty sequence).The

Combination Sum IIGiven a collection of candidate numbers (C) and a target number (T), find all unique combinations inC where the candidate numbers sums to T.Each number in C may only be used

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 is

Binary Tree Inorder TraversalGiven a binary tree, return the inorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3return [1,3,2].

Climbing StairsYou are climbing a stair case. It takes n steps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?先写个简单的递归，只能

Combination SumGiven a set of candidate numbers (C) and a target number (T), find all unique combinations inC where the candidate numbers sums to T.The same repeated number may be chosen fro

CombinationsGiven two integers n and k, return all possible combinations ofk numbers out of 1 ... n.For example,If n = 4 and k = 2, a solution is:[ [2,4], [3,4], [2,3], [1,2], [1

First Missing PositiveGiven an unsorted integer array, find the first missing positive integer.For example,Given [1,2,0] return 3,and [3,4,-1,1] return 2.Your algorithm should run in O(n)

Gray CodeThe gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integer n representing the total number of bits in the code, print the s

Implement strStr()Implement strStr().Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack.写了好几种求next数组的方法，都可以通过。class Solution {pub

Integer to RomanGiven an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999.class Solution {public: string intToRoman(int num) { st

Insert IntervalGiven a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially sorted according to their

Jump GameGiven an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.

Largest Rectangle in HistogramGiven n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.Abov

Length of Last WordGiven a string s consists of upper/lower-case alphabets and empty space characters' ', return the length of last word in the string.If the last word does not exist, return 0

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

Longest Common PrefixWrite a function to find the longest common prefix string amongst an array of strings.class Solution {public: string longestCommonPrefix(vector &strs) { if(0 =

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 su

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 fo

Longest Valid ParenthesesGiven a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.For "(()", the longest valid parenthe

Edit DistanceGiven two words word1 and word2, find the minimum number of steps required to convertword1 to word2. (each operation is counted as 1 step.)You have the following 3 operations perm

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:"((()))", "(()())", "(())

Interleaving StringGiven s1, s2, s3, find whether s3 is formed by the interleaving ofs1 ands2.For example,Given:s1 = "aabcc",s2 = "dbbca",When s3 = "aadbbcbcac", return true.When s3 =

Jump Game IIGiven an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.

Maximal RectangleGiven a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.O(N^3)class Solution {public: int maximalRectan

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)).O(N)

Maximum SubarrayFind the contiguous subarray within an array (containing at least one number) which has the largest sum.For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous suba

N-Queens IIFollow up for N-Queens problem.Now, instead outputting board configurations, return the total number of distinct solutions.class Solution {public: int totalNQueens(int n) {

Merge k Sorted ListsMerge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.class Solution {public: ListNode *mergeKLists(vector &lists) {

Minimum Window SubstringGiven a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n).For example,S = "ADOBECODEBANC"T = "ABC"

Multiply StringsGiven two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large and are non-negative.import java.math.Bi

Partition ListGiven a linked list and a value x, partition it such that all nodes less thanx come before nodes greater than or equal to x.You should preserve the original relative order of the

PermutationsGiven a collection of numbers, return all possible permutations.For example,[1,2,3] have the following permutations:[1,2,3], [1,3,2], [2,1,3], [2,3,1],[3,1,2], and[3,2,1].遍