atcoder-point-predictor | Predictor of difficulty of AtCoder 's problems | Learning library (2023)

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How do purely functional languages handle index-based algorithms?
How can I fix this : Warning: the fonts "Times" and "Times" are not available for the Java logical font "Serif"
Keras AttributeError: 'Sequential' object has no attribute 'predict_classes'
Getting error 'digital envelope routines', reason: 'unsupported', code: 'ERR_OSSL_EVP_UNSUPPORTED'
Vue 3 passing array warning: Extraneous non-props attributes were passed to component but could not be automatically inherited
TypeError: match.loader.options.plugins is not a function
Group and create three new columns by condition [Low, Hit, High]
What should the result be when assigning a variable to a reference to itself, in-between modified and then returned by a function call?
Flutter (2.5) - A splash screen was provided to Flutter, but this is deprecated


How do purely functional languages handle index-based algorithms?


2022-Apr-05 at 12:51

I have been trying to learn about functional programming, but I still struggle with thinking like a functional programmer. One such hangup is how one would implement index-heavy operations which rely strongly on loops/order-of-execution.

For example, consider the following Java code:



Answered 2022-Mar-07 at 21:17

This is not an index-heavy operation, in fact you can do this with a one-liner with scanl1 :: (a -> a -> a) -> [a] -> [a]:



How can I fix this : Warning: the fonts "Times" and "Times" are not available for the Java logical font "Serif"


(Video) E06 : Road Construction | Graph Algorithms | CodeNCode

2022-Mar-27 at 13:54

system:Mac OSsoftware:AnyLogic 8 Personal Learning Edition 8.7.6language: Java

When I run my model, the console print this info:

Warning: the fonts "Times" and "Times" are not available for the Java logical font "Serif", which may have unexpected appearance or behavior. Re-enable the "Times" font to remove this warning.



Answered 2021-Aug-01 at 11:11

We also recently had this issue on a mac running the latest public beta of Monterey.

For some reason the Times font was no longer installed or active on the Mac.

You can check in FontBook

You can simply reinstall it

I struggled to find a source online - her is one suggestion -



Keras AttributeError: 'Sequential' object has no attribute 'predict_classes'


2022-Mar-23 at 04:30

Im attempting to find model performance metrics (F1 score, accuracy, recall) following this guide

This exact code was working a few months ago but now returning all sorts of errors, very confusing since i havent changed one character of this code. Maybe a package update has changed things?

I fit the sequential model with, then used model.evaluate to find test accuracy. Now i am attempting to use model.predict_classes to make class predictions (model is a multi-class classifier). Code shown below:



Answered 2021-Aug-19 at 03:49

This function were removed in TensorFlow version 2.6.According to the keras in rstudio reference

update to





2022-Mar-11 at 10:51

I started learning about discord.js but now I am facing this issue.I tried some googling but couldn't manage to fix it.



Answered 2021-Aug-07 at 16:34

(Video) (2nd place) Codechef October Cook-off Screencast & Commentary

You need to specify the events which you want your bot to receive using gateway intents.

Instead of

const client = new Discord.Client();


const client = new Discord.Client({ intents: [Enter intents here] })

For example

const client = new Discord.Client({ intents: ["GUILDS", "GUILD_MESSAGES"] })

Here's another useful link:



Getting error 'digital envelope routines', reason: 'unsupported', code: 'ERR_OSSL_EVP_UNSUPPORTED'


2022-Mar-05 at 09:54

I got this error when learning Next.js, using npx create-next-app command according to site documentation here Everything works until I start the server,

Error stack:



Answered 2021-Nov-24 at 21:38

I found this solution

  1. if using bash just run NODE_OPTIONS=--openssl-legacy-provider before any command

  2. adding NODE_OPTIONS=--openssl-legacy-provider to package.json



Vue 3 passing array warning: Extraneous non-props attributes were passed to component but could not be automatically inherited


2022-Feb-26 at 21:48

please, I'm learning a VueJS 3 and I have probably begineer problem. I have warn in browser developer console like this one:

The Message is:



Answered 2021-Aug-16 at 13:32

The ItemProperties component has multiple root nodes because it renders a list in the root with v-for.

Based on the class name (infobox-item-properties), I think you want the class to be applied to a container element, so a simple solution is to just add that element (e.g., a div) in your component at the root:



TypeError: match.loader.options.plugins is not a function


2022-Feb-24 at 05:03

I am trying to use tailwindCSS in a ReactJS app

These are the scripts commands in package.json file



Answered 2021-Dec-18 at 22:00


Group and create three new columns by condition [Low, Hit, High]


2022-Feb-10 at 16:22

I have a large dataset (~5 Mio rows) with results from a Machine Learning training. Now I want to check to see if the results hit the "target range" or not. Lets say this range contains all values between -0.25 and +0.25. If it's inside this range, it's a Hit, if it's below Low and on the other side High.

I now would create this three columns Hit, Low, High and calculate for each row which condition applies and put a 1 into this col, the other two would become 0. After that I would group the values and sum them up. But I suspect there must be a better and faster way, such as calculate it directly while grouping. I'm happy for any idea.

Data ...


Answered 2022-Feb-10 at 16:13

You could use cut to define the groups and pivot_table to reshape:



What should the result be when assigning a variable to a reference to itself, in-between modified and then returned by a function call?


2022-Feb-02 at 00:42

#include int& addOne(int& x){ x += 1; return x;}int main(){ int x {5}; addOne(x) = x; std::cout << x << ' ' << addOne(x);}



Answered 2022-Feb-02 at 00:42

Since C++17 the order of evaluation is specified such that the operands of = are evaluated right-to-left and those of << are evaluated left-to-right, matching the associativity of these operators. (But this doesn't apply to all operators, e.g. + and other arithmetic operators.)

So in



Flutter (2.5) - A splash screen was provided to Flutter, but this is deprecated


2022-Jan-19 at 05:24

I am new to flutter and recently tried to develop a test app for learning sake with latest version Flutter 2.5. By looking at some tutorial online, I have added flutter_native_splash: ^1.2.3 package for splash screen. And works fine.

However, when I launch app for the first time, it shows following debug message

W/FlutterActivityAndFragmentDelegate(18569): A splash screen was provided to Flutter, but this is deprecated. See for migration steps.

After visiting the above link, I am not able to understand much what is supposed to be done.

Code in pubspec.yaml



Answered 2022-Jan-19 at 05:24

To avoid that warning you just need to remove that API usage from your project.Remove these lines of code from the AndroidManifest.xml file.

Previously, Android Flutter apps would either set in their application manifest, or implement provideSplashScreen within their Flutter Activity. This would be shown momentarily in between the time after the Android launch screen is shown and when Flutter has drawn the first frame. This is no longer needed and is deprecated – Flutter now automatically keeps the Android launch screen displayed until Flutter has drawn the first frame. Developers should instead remove the usage of these APIs. - source


As per the flutter 2.8.0 update, The newly created project doesn't have this warning.

They removed unused API from Androidmanifest.yml but still have belove mentioned code.


Community Discussions, Code Snippets contain sources that include Stack Exchange Network


No vulnerabilities reported

Install atcoder-point-predictor

You can download it from GitHub.
You can use atcoder-point-predictor like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.


For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

Find more information at:


Is AtCoder better than Codeforces? ›

Is AtCoder better than Codeforces? AtCoders problems give a new skillset to the coders. The questions are more attractive than Codeforces, and contests are held every week with high quality.

Can we use AtCoder library in codeforces? ›

Of course, this library is installed on the AtCoder server, and you can use it in our contests.

What is kyu in AtCoder? ›

Kyu is literally "level" and Dan can be seen as "rank". They're levels in Go (and several other Asian activities), like how people get chess titles on Codeforces.

What is AtCoder library? ›

We will publish AtCoder Library (ACL). This is a collection of implementation of various algorithms written by us. You can use it on most of our contests.

Who is the No 1 coder in Codeforces? ›

Z0RR0's blog
157 more rows

Who is number 1 on Codeforces? ›

Concluding Remarks
5 more rows

What is 1620B Codeforces? ›

Problem - 1620B - Codeforces. A rectangle with its opposite corners in (0,0) and (w,h) and sides parallel to the axes is drawn on a plane. You are given a list of lattice points such that each point lies on a side of a rectangle but not in its corner. Also, there are at least two points on every side of a rectangle.

What is 1676C Codeforces? ›

Problem - 1676C - Codeforces. You are given n words of equal length m, consisting of lowercase Latin alphabet letters. The i-th word is denoted si. In one move you can choose any position in any single word and change the letter at that position to the previous or next letter in alphabetical order.

Which book is best for Codeforces? ›

Books for Competitive Programming
  • Competitive Programming, by Steven and Felix Halim. ( ...
  • Programming Challenges: The Programming Contest Training Manual, by Steven Skiena and Miguel Revilla.
  • Competitive Programmer's Handbook, by Antti Laaksonen. (

What does re mean in AtCoder? ›

About Judging Status
StatusWhat it means
RE (Runtime Error)An error occurred while running the program. There is an error that was not detected while compiling. Possible causes could be stack overflow, division by zero, etc.
OLE (Output Limit Exceeded)The output size is exceeding the size limit assigned to the problem.
5 more rows
Apr 25, 2015

What is AtCoder heuristic? ›

About AtCoder Heuristic Contest(AHC)

Unlike algorithm contests such as ABC/ARC/AGC, the goal is to create a better solution to a problem for which it is difficult to find the optimal solution. For examples of problems, see past contests of similar format.

Is CodeChef good for beginners? ›

CodeChef provides a lucrative user-friendly platform for a beginner to expert coders to participate and hone their skills in competitive coding. You can also be benefited from the hiring challenges in which in any contest the hiring partners can also contact the top performers for active software developer roles.

How does library code work? ›

Library code is organized in such a way that it can be used by multiple programs that have no connection to each other, while code that is part of a program is organized to be used only within that one program.

Who is the fastest coder? ›

As of December 2022, Gennady is the highest-rated programmer on CodeChef, Topcoder, AtCoder and HackerRank. In January 2022, he achieved a historic rating of 3979 on Codeforces, becoming the first to break the 3900 barrier.

Who is the greatest coder of all time? ›

6 Best Programmers of All Time
  • Dennis Ritchie. Dennis Ritchie. Dennis Ritchie was an American computer scientist who helped shape the digital era. ...
  • Bjarne Stroustrup. Bjarne Stroustrup. ...
  • James Gosling. James Gosling. ...
  • Linus Torvalds. Linus Torvalds. ...
  • Anders Hejlsberg. Anders Hejlsberg. ...
  • Donald Knuth. Donald Knuth.

What is 2050 number Codeforces? ›

Problem - 1517A - Codeforces. A number is called 2050-number if it is 2050, 20500, ..., (2050⋅10k for integer k≥0). Given a number n, you are asked to represent n as the sum of some (not necessarily distinct) 2050-numbers. Compute the minimum number of 2050-numbers required for that.

What is Codeforces salary? ›

Average annual salary in CodeForce is INR 28.8 lakhs .

How to reach 1200 in Codeforces? ›

If your rating is under 1200, read the next part and practice. If you use div3, you'll need to solve 3 problems in 30 minutes. That means you should solve div3C in 15 minutes. To practice it, you may choose 1000~1200 rated problem and try to solve it in 15 mins.

What is Div 4 in Codeforces? ›

This is a forced measure for combating with unsporting behavior. To qualify as a trusted participants of the fourth division, you must: take part in at least two rated rounds (and solve at least one problem in each of them), do not have a point of 1600 or higher in the rating.

What is 1747 codeforces? ›

Problem - 1747A - Codeforces. You are given an array a consisting of n integers. You want to distribute these n integers into two groups s1 and s2 (groups can be empty) so that the following conditions are satisfied: For each i (1≤i≤n), ai goes into exactly one group.

What is 1741B codeforces? ›

Problem - 1741B - Codeforces. A sequence of n numbers is called permutation if it contains all numbers from 1 to n exactly once. For example, the sequences [3,1,4,2], [1] and [2,1] are permutations, but [1,2,1], [0,1] and [1,3,4] are not.

What is C in codeforces? ›

C is one of the most popular languages out there for programming lower level things like operating systems and device drivers, as well as implementing programming languages. C is a very easy to learn middle level language for expressing ideas in programming in a way that most people are comfortable with.

What is 1411A codeforces? ›

Problem - 1411A - Codeforces. You have been assigned to develop a filter for bad messages in the in-game chat. A message is a string S of length n, consisting of lowercase English letters and characters ')'.

What is 1003B codeforces? ›

Problem - 1003B - Codeforces. You are given three integers a, b and x. Your task is to construct a binary string s of length n=a+b such that there are exactly a zeroes, exactly b ones and exactly x indices i (where 1≤i<n) such that si≠si+1. It is guaranteed that the answer always exists.

What is 1717C codeforces? ›

Problem - 1717C - Codeforces. Given an array of integer a1,a2,…,an. In one operation you can make ai:=ai+1 if i<n and ai≤ai+1, or i=n and ai≤a1. You need to check whether the array a1,a2,…,an can become equal to the array b1,b2,…,bn in some number of operations (possibly, zero).

How hard is it to get red on Codeforces? ›

It is possible only for very experienced user. In order to know about newcomers it looks reasonably to drop out all profiles who became blue at the very first contest and reached red points more quickly than tourist :-) There are only 784 users who fit these conditions.

Is Codeforces harder than LeetCode? ›

The problem difficulty range on LeetCode compared to a traditional competitive programming platform like Codeforces looks something like this: LeetCode includes the easiest of easy problem, like the classic FizzBuzz problem. Codeforces doesn't bother with problems as easy as that.

Which division is easiest in Codeforces? ›

Beginners should participate in Division 3 contests and work their way up for the best results.

What is the TopCoder rating system? ›

TopCoder rating system is an example of Bayesian rating system. In general this probably means that potential of each coder is decribed by 2 values: the mean and the standard deviation (SD). When comparing 2 coders, not only their rating is considered, but also the volatility.

What is a heuristic Apcsp? ›

Heuristic. a problem solving approach (algorithm) to find a satisfactory solution where finding an optimal or exact solution is impractical or impossible.

What is a heuristic model machine learning? ›

Heuristics are used in machine learning (ML) and artificial intelligence (AI) when it's impractical to solve a particular problem with a step-by-step algorithm. Because a heuristic approach emphasizes speed over accuracy, it is often combined with optimization algorithms to improve results.

What are heuristic methods in software engineering? ›

In mathematical optimization and computer science, heuristic (from Greek εὑρίσκω "I find, discover") is a technique designed for solving a problem more quickly when classic methods are too slow for finding an approximate solution, or when classic methods fail to find any exact solution.

How long does it take to become a 5 star coder? ›

Give each and every contest for let's say 3 months. Try to upsolve as much as you can. You can learn algorithms as well during/after contest by searching it what you wanna do on Google appropriately as and when required. I knew nothing about competitive and it took me 11 contests ( 4 months) to become 5 star.

How hard is it to get 4 star in CodeChef? ›

It depends on your performance in Contests. You should top (maybe stand in the top 100 in short contests) at least 2 contests to become 4*. If your performance is just above what is expected, your rating increases but very little. This way, it may even take 3 - 4 months to cross 1800.

How hard is it to become a 5 star coder at CodeChef? ›

Becoming a 5 star coder at codechef is no small feat, and it's something to be very proud of. But it's also important to remember that there is always more to learn. As coders, we should never rest on our laurels but instead continue to push ourselves to new levels.

Do librarians need to code? ›

Yes, there are some threshold concepts to which all librarians should be exposed: organization of information, archiving, research methods, and, yes, coding (and a great many more).

What is the coding system for library books? ›

Libraries in the United States generally use either the Library of Congress Classification System (LC) or the Dewey Decimal Classification System to organize their books. Most academic libraries use LC, and most public libraries and K-12 school libraries use Dewey.

Why use libraries in coding? ›

Programming libraries are useful tools that can make a web developer's job more efficient. They provide pre-written, reusable chunks of code that developers can use to create applications quickly and easily.

Which editor is best for competitive programming Codeforces? ›

CP Editor is Fast written in Native C++ (Qt), Cross-platform (works everywhere), and has all basic features that a competitive programmer needs from an editor.

Who is the best competitive coder in the world? ›

Petr Mitrichev is a Competitive Programmer from Russia and have studied at Moscow State University. He works at Google as of 2021 on Google Search Engine. Petr is one of the original Competitive Programmers who demonstrated consistent performance. He has won all Major Competitive Programming contest at some point.

Who is the top Python coder in Codeforces? ›

As of December 2022, Gennady is the highest-rated programmer on CodeChef, Topcoder, AtCoder and HackerRank. In January 2022, he achieved a historic rating of 3979 on Codeforces, becoming the first to break the 3900 barrier.

Which is tougher Codeforces or codechef? ›

Codechef organises a 10 day long contest (good for beginners), Codeforces doesn't. I personally feel codechef is better for beginners to practise as the have a lot of problems sorted according to difficulty level. And also as @bansal1232 said codechef organises one of the largest competition of the world ACM_ICPC.

Who has solved the most problems on Codeforces? ›

2- The maximum number of unsuccessful submissions before getting a problem accept in a contests is 81, made by shahbox in Codeforces Beta Round 44 (Div. 2): standings 518th place. 3- The user who solved the maximum number of problems during all Codeforces contests is Egor, he solved 453 problems.

Can I become expert in Codeforces? ›

First, you should learn about the algorithms. First, you need to know the concept of them, and you should practice. Practicing these algorithms can be done by solving 1300~1500 rated problems having these tags. You should see editorials quickly(15 mins) to learn fast.

Is Python good for Codeforces? ›

Python is a great programming language: simple, expressive, compact. In Codeforces, Python is often the best choice for Div 2 A and B problems.

What is the highest coder salary? ›

Highest salary that a Coder can earn is ₹10.0 Lakhs per year (₹83.3k per month).

Who is the youngest coder in the world? ›

Learn coding and robotics with the world's youngest computer programmer. His name is Saion Gupta and he was just 12 years 254 days old when he officially broke the record in November 2022.

What is the hardest coding competition? ›

1) The ACM-ICPC International Collegiate Programming Contest

The contest fosters creativity, teamwork, and innovation in building new software programs, and enables students to test their ability to perform under pressure. Quite simply, it is the oldest, largest, and most prestigious programming contest in the world.

What is the highest salary in Python code? ›

Python Developer salary in India ranges between ₹ 1.4 Lakhs to ₹ 9.0 Lakhs with an average annual salary of ₹ 4.0 Lakhs.

Who is the 7 star coder on CodeChef? ›

This week's guest on Weekend With Champions is Chinmay Pani, a 7-Star coder on CodeChef currently working as an Analyst at Goldman Sachs. Having worked as a SDE intern at Amazon, Chinmay credits competitive programming to be one of the biggest reasons for his success.


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