计数信号量用来控制同时访问某个特定资源的操作数或同时执行某个指定操作的数量 A counting semaphore.Conceptually, a semaphore maintains a set of permits. Each acquire blocks if necessary until a permit is available, and then takes it. Each release adds a permi…
题目描述 给定一张地势图,所有的点都被水淹没,现在有一些关键点,要求放最少的水泵使所有关键点的水都被抽干 输入输出格式 输入格式: In the first line of the standard input there are two integers and , separated by a sin…
[OpenGL ES 03]3D变换:模型,视图,投影与Viewport 罗朝辉 (http://blog.csdn.net/kesalin) 本文遵循“署名-非商业用途-保持一致”创作公用协议 系列文章:[OpenGL ES 01]OpenGL ES之初体验[OpenGL ES 02]OpenGL ES渲染管线与着色器…
摘抄自:https://segmentfault.com/a/1190000003554858#articleHeader2 题目: Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example: Given the below binary tree, 1/ \2 3Return 6. 思…
<?phpclass Db{//私有静态属性存储实例化对象自身private static $instance;//存储PDO类的实例化private $pdo;//PDOStatement类private $stmt;//禁止外部实例化对象,链接数据库private function __construct($config,$port,$charset){try{$this->pdo new P…