Awy

摘要： Given two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large and are non-nega... 阅读全文

摘要： Given 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].思路：这道题就是把区间数重合... 阅读全文

摘要： 面向对象的编程，并不是类越多越好，类的划分是为了封装，但分类的基础是抽象，具有相同属性和功能的对象的抽象集合才是类。 在说策略模式之前，我们想用简单工厂模式来实现商场收银程序#include using namespace std;//现金收费抽象类class CashSuper{public... 阅读全文

摘要： Given a stringsand a dictionary of wordsdict, add spaces insto construct a sentence where each word is a valid dictionary word.Return all such possibl... 阅读全文

摘要： Given a stringsand a dictionary of wordsdict, determine ifscan be segmented into a space-separated sequence of one or more dictionary words.For exampl... 阅读全文

摘要： 工厂方法模式（Factory Method），定义一个用于创建对象的接口，让子类决定实例化哪一个类。工厂方法使用一个类的实例化延迟到其子类。根据依赖倒转原则，我们把工厂类抽象出一个接口，这个接口只有一个方法，就是创建抽象产品的工厂方法。然后，所有的要生产具体类的工厂，就去实现这个接口，这样，一个... 阅读全文

摘要： 简单工厂模式没有抽象类，只有一个具体工厂类，所有产品的生产都由这个工厂类的对象来负责，如果这个工厂类中生产产品的方法被声明为静态的，那么连这个工厂对象也不是必须的了，直接使用工厂类名就可以调用生产方法。生产方法被声明为静态的，所以简单工厂模式也叫静态工厂模式。简单工厂模式并不是一个好的设计模式，... 阅读全文

摘要： Given a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there exists one unique longest pa... 阅读全文

摘要： The 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... 阅读全文

摘要： Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character'.'.You may assume that there will be on... 阅读全文

摘要： Implement strStr().Returns a pointer to the first occurrence of needle in haystack, ornullif needle is not part of haystack.思路：这是一道字符串匹配的函数，就是找出needle... 阅读全文

摘要： Givennnon-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histog... 阅读全文

摘要： Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.思路：本题给你包含0和1的矩阵，让你找出包含1的最大矩阵，并返回其... 阅读全文

摘要： Clone an undirected graph. Each node in the graph contains alabeland a list of itsneighbors.OJ's undirected graph serialization:Nodes are labeled uniq... 阅读全文

摘要： Given an arraySofnintegers, are there elementsa,b,c, anddinSsuch thata+b+c+d= target? Find all unique quadruplets in the array which gives the sum of ... 阅读全文

摘要： Implementint sqrt(int x).Compute and return the square root ofx.思路：二分查找法解决这道题class Solution {public: int sqrt(int x) { if(x1e-6) { ... 阅读全文

摘要： Given a list, rotate the list to the right bykplaces, wherekis non-negative.For example:Given1->2->3->4->5->NULLandk=2,return4->5->1->2->3->NULL.思路：这道... 阅读全文

摘要： Given an unsorted integer array, find the first missing positive integer.For example,Given[1,2,0]return3,and[3,4,-1,1]return2.Your algorithm should ru... 阅读全文

摘要： Given a strings1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible representation... 阅读全文

摘要： Say you have an array for which theithelement is the price of a given stock on dayi.Design an algorithm to find the maximum profit. You may complete a... 阅读全文

摘要： Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Pana... 阅读全文

摘要： Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters fo... 阅读全文

摘要： A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.Return a deep copy ... 阅读全文

摘要： You 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 ... 阅读全文

摘要： Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note:A solution using O(n) space is ... 阅读全文

摘要： Given an array of strings, return all groups of strings that are anagrams.Note: All inputs will be in lower-case.思路：回文构词法是由颠倒字母顺序而来的单词。主要的特点就是字母个数和种类都... 阅读全文

摘要： The 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 fo... 阅读全文

摘要： Mergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity.思路：合并k个有序链表为一个有序链表。我们可以用先合并两个链表的方法，然后逐个遍历链表数组，与上一个合并结束... 阅读全文

摘要： Given a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from the orig... 阅读全文

摘要： There areNgas stations along a circular route, where the amount of gas at stationiisgas[i].You have a car with an unlimited gas tank and it costscost[... 阅读全文