非线程安全 //初始化火车票数量.卖票窗口(非线程安全).并开始卖票 - (void)initTicketStatusNotSave { // 1. 设置剩余火车票为 50 self.ticketSurplusCount = ; // 2. 设置北京火车票售卖窗口的线程 self.ticketSaleWindow1 = [[NSThread alloc]initWithTarget:self selector:@selector(saleTicketNotSafe) object:nil]; s…

这篇博客是接着总篇iOS GCD NSOperation NSThread等多线程各种举例详解写的一个支篇.总篇也包含了此文的链接.本文讲解的知识点有NSThread的开始.取消.在当前线程执行任务.线程通信.线程同步.延时函数等.附上:demo下载地址. 一.NSThread介绍 优点:NSThread 比其他两个轻量级. 缺点:需要自己管理线程的生命周期,线程同步.线程同步对数据的加锁会有一定的系统开销. 二.开始和取消 举个例子,注释写的很详细,不多说啦. //开始 - (IBAction…

题目链接:Path Sum II | LeetCode OJ Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2],…

题目链接:Populating Next Right Pointers in Each Node II | LeetCode OJ Follow up for problem "Populating Next Right Pointers in Each Node". What if the given tree could be any binary tree? Would your previous solution still work? Note: You may only u…

原文标题:Functional Android (II): Collection operations in Kotlin 原文链接:http://antonioleiva.com/collection-operations-kotlin/ 原文作者:Antonio Leiva(http://antonioleiva.com/about/) 原文发布:2015-09-29 在简化代码方面,Lambda表达式是一个杰出的工具,而且还可以完成之前不可能完成的事.我们在这个系列文章的第一篇(Unlea…

本文并非最终版本,如有更新或更正会第一时间置顶,联系方式详见文末 如果觉得本文内容过长,请前往本人 “简书” 本文源码 Demo 详见 Githubhttps://github.com/shorfng/iOS-4.0-multithreading.git 因为Pthread很少用到,所以对于Pthread的知识没有抠那么细致,所以将Pthread和 NSThread放在了一起. 4.1 Pthread 4.1-1.0 创建线程 - pthread_create /* <#pthread_t *r…

统计分析中Type I Error与Type II Error的区别 在统计分析中,经常提到Type I Error和Type II Error.他们的基本概念是什么?有什么区别? 下面的表格显示 between truth/falseness of the null hypothesis and outcomes of the test " -------|-------|------- | Judgement of Null Hypothesis H0 | Valid | Invalid |…

题意: 给你一个数n,表示有n辆火车,编号从1到n,入站,问你有多少种出站的可能.    (题于文末) 知识点: ps:百度百科的卡特兰数讲的不错,注意看其参考的博客. 卡特兰数(Catalan):前几项为 : 1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, 9694845, 35357670- 令h(0)=1,h(1)=1,catalan数满足递推式:      h(n)= h(0…

We are playing the Guess Game. The game is as follows: I pick a number from 1 to n. You have to guess which number I picked. Every time you guess wrong, I'll tell you whether the number I picked is higher or lower. However, when you guess a particula…

A 2d grid map of m rows and n columns is initially filled with water. We may perform an addLand operation which turns the water at position (row, col) into a land. Given a list of positions to operate, count the number of islands after each addLand o…