Programmer Think

There are four types of internal purchase: consumer goods, non consumer goods, non renewal subscription and automatic renewal subscription. As the name suggests, the most difficult is the implementation of automatic renewal subscription. After opening automatic renewal subscription, the processing of subscription members will encounter the foll ...

Files and streams Due to the needs of the project, it is required to output the image data to the file after processing. In the file, different kinds of data will be displayed in table layout. At first, it was not easy to do, and then try it 1. Basic knowledge To process files in C + +, you must include header files and in the C + + source ...

  in actual development, NSNotification can well decouple code and transmit data across layers. But because it is globally effective. Therefore, sometimes we don't want to have such a wide range of functions, but just want to send and receive notifications within a certain range. Recently, I made a plan to share with you. My side is mainly ...

A classical probability problem   Competition home page   My submission Time limit: 1 second for C / C + + and 2 seconds for other languages Space limitation: C / C + + 26244k, other languages 524288K 64bit IO Format: %lld Title Description   Students bit noob and lit noob (hereinafter referred to as B and L) of Niuniu univ ...

Requirements: some time ago, when developing a project, there was a requirement. Because some information of the APP is sensitive, if the user presses the home key to return to the background during the operation of the APP, after the specified time, and then switches to the foreground, it is necessary to verify the fingerprint or gesture set b ...

Given a different set of words, find all the different index pairs (i, j) so that two words in the list, words[i] + words[j], can be stitched together into palindrome strings. Example 1: Input: words = ["abcd","dcba","lls","s","sssll"] Output:[[0,1],[1,0],[3,2],[2,4]] Interpretation: A spliceable palindrome string is ["dcbaabcd","abcddcba"," ...

This paper mainly introduces the common locks and the underlying analysis of synchronized, NSLock, recursive lock and conditional lock   lock Refer to the performance data comparison diagram of a lock, as shown below Lock performance comparison It can be seen that the lock performance in the figure is from high to low: osspinlock - > d ...

Download a fighting fish first (you can do it without downloading, the URLs are all here, right) Grab a json package by grabbing it and get the address below   Observed tests show that modifying offset values is equivalent to paging an app Accessing this url returns a large dictionary with two indexes, one error and one data.Data is another 20 ...

preface iOS crash is a headache for iOS developers. App crashes, indicating that there is a problem in code writing. It is very important to quickly locate the crash site. It's easier to find the problem in the debugging phase, but it's more troublesome to analyze the crash report of the app that has been launched. This article will summarize a ...

Write at the beginning Recently, the official account of React-native is the main attack. By the way, I will review the next React-native. Node.js And cross platform direction, architecture and Debug If you are interested in the proposal, we should recommend the following official account. https://mp.weixin.qq.com/s/RsvI5AFzbp3rm6sOlTmiYQ Of ...