Programmer Group

1. Insert operation details Insert a document db.collection.insertOne() db.inventory.insertOne( { item: "canvas", qty: 100, tags: ["cotton"], size: { h: 28, w: 35.5, uom: "cm" } } ) Insert multiple documents db.collection.insertMany() db.inventory.insertMany([ { item: "journal", qty: 25, tags: [" ...

Written in front It will be 2020 soon. Do you know that my friends have learned css3 animation this year? Speaking of css animation is a very awkward thing. On the one hand, because the company uses less css animation, on the other hand, most developers are accustomed to using JavaScript to do animation, so many programmers are more excluded to ...

Title: Give n points and M pipes. Each pipe is used to flow liquid. One way, the material flowing in each pipe at every moment is equal to the material flowing out. Make m pipes form a cycle body, in which the material flows. The flow limit of each pipe is [Li,Ri]. That is to say, the flow in at every time should not exceed RI (maximum flow p ...

Some apps may make a lot of content into a high-definition picture to the mobile terminal for loading (our project is...), if the picture is small, it's OK, but if the picture is too large (we have more than 2M, MMP), it's either not displayed, or it's not always fuzzy. So what should we do? Use BitmapRegionDecoder to segment and then splice th ...

The K-th largest element in the LeetCode703 data stream Design a class to find the K-th largest element in the data flow. Note that it is the K-th largest element after sorting, not the K-th different element. Your KthLargest class needs a constructor that receives both the integer K and the integer a ...

I. what is AQS? AQS is the abbreviation of abustatqueuedsynchronizer. It is a Java provided underlying synchronization tool class. It uses an int type variable to represent the synchronization state, and provides a series of CAS operations to manage the synchronization state. The main function of AQS is to provide unified underlying support fo ...

1: stack A practical requirement of 1.1 stack Please enter an expression Calculation formula: [7 * 2 * 2-5 + 1-5 + 3-3] Click to calculate [as shown below]   Excuse me: how does the bottom layer of the computer calculate the result? Note that it's not a simple operation to list the formula, beca ...

The purple book says that this question is a basic exercise for beginners (yes, it seems to be customized for me After five or six days of training, I didn't do the question, so I chose this question with a recovery point mentality. Who ever thought that not only did not recover, but also really gave me ...

Catalog I. overview II. Renderings III. source code explanation 1. Source code structure 2. Header file 3. Add cursor 4. Monitoring movement 5. Move cursor 6. Other functions IV. test method 1. Test project 2. Test documents 3. Test co ...

DNFS is a new feature introduced by Oracle 11g to improve the IO performance of the system with NFS. Compared with system level NFS, DNFS reduces the consumption of network and IO transmission. The reasons for the low IO capacity of normal NFS are:1. Low efficiency data transmission, multi link implementation is difficult;2. The system's RPC s ...