wxquare的学习笔记

摘要： Givenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a total of 5 unique BST's. 1... 阅读全文

摘要： 一、进程是如何进行网络通信的？socket通信的过程？ 同一机器上的不同进程之间的通信方式有很多种，主要使用消息传递或共享内存。而跨网络的进程是几乎都是使用socket通信，例如web服务器，QQ。 socket即是一种特殊的文件，操作系统提供了一些socket函数就是对其进行的操作（读/写IO... 阅读全文

摘要： 一、问题 如何设计一容器能包含彼此不同而又相互关联的类的对象（处于完整的继承层次的类）？因为一般的数组容器都只能包含一种类型的对象。 假设有一个表示不同类型的交通工具的类的派生层次： class Vehicle{public: virtual double weight () cons... 阅读全文

摘要： Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjac... 阅读全文

摘要： Givennpairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, givenn= 3, a solution set is:"((()))... 阅读全文

摘要： 1.Given a set of candidate numbers (C) and a target number (T), find all unique combinations inCwhere the candidate numbers sums toT.Thesamerepeated n... 阅读全文

摘要： Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example:Given "25525511135",return ["255... 阅读全文

摘要： 一、N-QueensII 1 class Solution { 2 public: 3 int totalNQueens(int n) { 4 int total = 0; 5 vector v(n,0); 6 dfs(0,n,total,v)... 阅读全文

摘要： Follow up for ”Unique Paths”:Now consider if some obstacles are added to the grids. How many unique paths would there be?An obstacle and empty space i... 阅读全文

摘要： Clone an undirected graph. Each node in the graph contains alabeland a list of itsneighbors. 1 /** 2 * Definition for undirected graph. 3 * struct U... 阅读全文