第一次codeforces竞技结束 #238 Div 2
Little Chris is a huge fan of linear algebra. This time he has been given a homework about the unusual square of a square matrix. The dot product of two integer number vectors x and y of size n is the sum of the products of the correspondi
Little Chris is a huge fan of linear algebra. This time he has been given a homework about the unusual square of a square matrix.
The dot product of two integer number vectors x and y of size n is the sum of the products of the corresponding components of the vectors. Theunusual square of an n?×?n square matrix A is defined as the sum of n dot products. The i-th of them is the dot product of the i-th row vector and the i-th column vector in the matrix A.
Fortunately for Chris, he has to work only in GF(2)! This means that all operations (addition, multiplication) are calculated modulo 2. In fact, the matrix A is binary: each element of A is either 0 or 1. For example, consider the following matrix A:
The unusual square of A is equal to (1·1?+?1·0?+?1·1)?+?(0·1?+?1·1?+?1·0)?+?(1·1?+?0·1?+?0·0)?=?0?+?1?+?1?=?0.
However, there is much more to the homework. Chris has to process q queries; each query can be one of the following:
- given a row index i, flip all the values in the i-th row in A;
- given a column index i, flip all the values in the i-th column in A;
- find the unusual square of A.
To flip a bit value w means to change it to 1?-?w, i.e., 1 changes to 0 and 0 changes to 1.
Given the initial matrix A, output the answers for each query of the third type! Can you solve Chris's homework?
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
When will Teamfight Tactics S11 end?
Mar 18, 2024 pm 03:16 PM
Each season of Teamfight Tactics lasts about three months. Currently, the US test server of Teamfight Tactics S11 season will be updated and launched on March 7. Teamfight Tactics and Golden Shovel will be updated and launched on March 21. It is speculated that the S11 season It will probably end in early July. When will TFT S11 end? Answer: Early July. 1. It is speculated that the S11 season will end in early July. The specific end date needs to wait for the official announcement. 2. Each season of Teamfight Tactics lasts about three months. 3. The US test server of Teamfight Tactics S11 season will be updated and launched on March 7, and Teamfight Tactics and Golden Shovel will be updated and launched on March 21. 4. A new gameplay mechanism will be added to the S11 season, and more than 20 new Ornn artifacts will be added.
How to quickly turn off the shortcut keys running in the background of Win11?
Dec 28, 2023 am 09:54 AM
When we use computers, we will inevitably encounter a lot of problems that keep running in the background, which slows down the system. At this time, is there a shortcut key to end the background running in win11? In fact, we can only open the task manager with the shortcut key and then close it. Backstage. Shortcut keys to end background running in win11: 1. First, we press the "ctrl+shift+esc" shortcut key combination on the keyboard to open the task manager page. 2. In the Task Manager page, use the mouse to click and select the "Name" button option. 3. After the page jumps, we can directly see all the "background processes" currently running. 4. According to actual needs, we select the background that we want to close, and click "End Task" in the lower right corner of the option.
How to use computer task manager shortcut keys to end a task
Jan 02, 2024 pm 01:34 PM
Many friends encounter certain software getting stuck when using their computers. If the computer cannot move, you need to call up the task manager to end the process. After calling it out, how to use the shortcut keys to end the task? The simplest is to delete, and there are other methods. Let’s take a look. Take a look. How to use the shortcut keys for ending tasks in Task Manager How to use the shortcut keys for Task Manager: 1. Key combination "Ctrl+Shift+ESC". 2. Key combination "Ctrl+Alt+Delete". Shortcut keys for ending tasks 1. Select the task to be ended and click "Delete". 2. Select the task that needs to be ended and press the key combination "alt+e".
How to use css to realize that a div is missing a corner
Jan 30, 2023 am 09:23 AM
CSS method to realize that a div is missing a corner: 1. Create an HTML sample file and define a div; 2. Set the width and height background color for the div; 3. Add a pseudo class to the div that needs to delete a corner, and set the pseudo class to Use the same color as the background color, then rotate it 45 degrees, and then position it to the corner that needs to be removed.
How to end a meeting in Tencent Meeting - specific operations for ending a meeting in Tencent Meeting
Mar 05, 2024 pm 12:16 PM
Do you often use Tencent Conference software in the office? So do you know how to end a meeting in Tencent Conference? Next, the editor will bring you the specific operations of ending a meeting in Tencent Conference. Users who are interested in this will share with you Let’s take a look below. Turn on the computer, double-click to enter Tencent Meeting, then log in, click to enter the quick meeting, and click the end meeting button.
Implementation of word-marking translation browser script based on ChatGPT API
May 01, 2023 pm 03:28 PM
Preface Recently, there is a browser script based on ChatGPTAPI on GitHub, openai-translator. In a short period of time, the star has reached 12k. In addition to supporting translation, it also supports polishing and summarizing functions. In addition to browser plug-ins, it also uses tauri packaging. If you have a desktop client, aside from the fact that tauri uses the rust part, the browser part is still relatively simple to implement. Today we will implement it manually. The interface provided by openAI, for example, we can copy the following code and initiate a request in the browser console to complete the translation //Example constOPENAI_API_KEY="s
What is the difference between iframe and div
Aug 28, 2023 am 11:46 AM
The difference between iframe and div is that iframe is mainly used to introduce external content, which can load content from other websites or divide a web page into multiple areas. Each area has its own independent browsing context, while div is mainly used to divide and organize content. block for layout and style control.
What is the div box model
Oct 09, 2023 pm 05:15 PM
The div box model is a model used for web page layout. It treats elements in a web page as rectangular boxes. This model contains four parts: content area, padding, border and margin. The advantage of the div box model is that it can easily control the layout of the web page and the spacing between elements. By adjusting the size of the content area, inner margin, border and outer margin, various layout effects can be achieved. The box model also provides some Properties and methods can dynamically change the style and behavior of the box through CSS and JavaScript.
