如何證明素數有無窮多個呢?和勾股定理一樣,有很多證明方法,也是異彩紛呈。好多證明方法都是神證明(經典證明:素數無窮多的拓撲學證明)。有一本書叫做Proofs from THE BOOK ,中文譯名 來自聖經的證明 ,這本書就是專門搜集這些神證明的。顯然BOOK 在英文中就指聖經。不過,個人覺得翻譯成 來自天書的證明
I recommend using the -[NSNumber objCType] method.It allows you to do:NSNumber * n = [NSNumber numberWithBool:YES];if (strcmp([n objCType], @encode(BOOL)) == 0) { NSLog(@"this is a bool");} else if (strcmp([n objCType], @encode(int)) == 0) {
之前提到過我在家裡拿筆記本充當了伺服器,那隻是一半,現在要說的是另一半:這個伺服器上所啟動並執行網站是 http://labs.richardbao.com/其實並沒有多少東西可放,但我也不喜歡看它永遠是正在建設中的狀態,於是我收拾了一些舊的東西開始堆在上面。Windows Live 驗證組成,這個是去年在北京的時候做的。功能在於在網站中整合 Windows Live ID 的身分識別驗證,並在得到使用者許可的情況下,讀取 Live Messenger 的連絡人清單。UX Guide
Collisions and Collectables: How To Make a Tile Based Game with Cocos2D Part 2Like this post? Follow me on Twitter!Mmm, that was tasty!This is the second part of a 2-part tutorial where we cover how to make a tile based game with Cocos2D and the
Harder Monsters and More Levels: How To Make A Simple iPhone Game with Cocos2D Part 3Like this post? Follow me on Twitter!Watch out for the green guy!So far, the game we’ve been making in How To Make A Simple iPhone Game with Cocos2Dis pretty cool.
Rotating Turrets: How To Make A Simple iPhone Game with Cocos2D Part 2Like this post? Follow me on Twitter!Let's Rotate This Turret!There’s been a surprising amount of interest in the post on How To Make a Simple iPhone Game with Cocos2D – and