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553. Optimal division [medium question] [daily question] Idea: [mathematical method] Let the optimal solution of dividing these n numbers be Fn=x/y. obviously, if the numerator is as large as possible and the denominator is as small as possible, the result will be the largest. Because nums are all positive integers greater than 1, the smal ...

Interface Overview Interface is a reference type in the Java language and a "collection" of methods. Therefore, the interior of the interface is mainly to define methods, including constants, abstract methods (JDK 7 and before), default methods and static methods (JDK 8), and private methods (jdk9). There can be no other members in t ...

1 zset zset (ordered set) is the most frequently asked data structure in Redis. This ordered set is similar to the set container of C + +, but the underlying structure is different. The underlying structure of C + + is implemented using RB tree (red black tree). Unlike zset, which is implemented using a hop table. On the one hand, zset ensure ...

What happens in the process of new an object?1. Confirm whether class meta information exists. When the JVM receives the new instruction, it first checks whether the class meta information to be created exists in the metaspace. If it does not exist, use the current class loader to find the corresponding class file with ClassLoader + package nam ...

Technical backgroundBefore realizing the front-end device access of GB28181 on Android platform, we had very mature RTMP push, RTSP push and lightweight RTSP service modules a few years ago, especially RTMP push, which is widely used in the industry. Many developers may ask, since we have the above modules, why do we need to realize the front-e ...

1. Overview of OS command injection Background: when programmers use script language (such as PHP) to develop applications, script language development is very fast, concise and convenient, but it is also accompanied by some problems, such as slow speed, unable to touch the bottom of the system, etc. When developing applications, especiall ...

Template meta programming example - how to design a general geometry Library design principle Suppose you need to use a c + + program to calculate the distance between two points You might do this: First define a struct: struct mypoint { double x, y; }; Then define a function containing the calculation algorithm: double distance(myp ...

2, Encapsulation (Part 2) 4.1 object arrays and object members (1) Object array Many times, we need not only one object, but a group of objects. For example, if there are 50 students in a class, we can use the object array. [object array code practice] Title: define a Coordinate class whose data members contain abscissa and ordinate. In ...

1. Details of springboot 1.1 environment switching explain: Software generally runs in many different environments There is a dev environment in the development phase Testing will be carried out after development There will be a test environment The final project is deployed to the user's service There will be a production environment   Qu ...

Binary sort tree Requirements: for a sequence (7, 3, 10, 12, 5, 1, 9), it is required to query and add data efficiently Basic introduction: Binary sort tree: BST: (Binary Sort(Search) Tree). For any non leaf node of the binary sort tree, the value of the left child node is required to be smaller than that of the current node, and the valu ...