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Sudoku for Beginners: How to Improve Your Problem-Solving Skills

Are you a beginner when it comes to solving Sudoku puzzles? Do you find yourself frustrated and unsure of where to start? Fear not, as we have compiled a comprehensive guide on how to improve your problem-solving skills through Sudoku.

Understanding the Basics of Sudoku

Before we dive into the strategies and techniques, let’s first understand the basics of Sudoku. A Sudoku puzzle is a 9×9 grid that is divided into nine smaller 3×3 grids. The objective is to fill in each row, column, and smaller grid with numbers 1-9 without repeating any numbers.

Starting Strategies for Beginners

As a beginner, it can be overwhelming to look at an empty Sudoku grid. But don’t worry. There are simple starting strategies that can help you get started. First, look for any rows or columns that only have one missing number. Fill in that number and move on to the next row or column with only one missing number. Another strategy is looking for any smaller grids with only one missing number and filling in that number.

Advanced Strategies for Beginner/Intermediate Level

Once you’ve mastered the starting strategies, it’s time to move on to more advanced techniques. One technique is called “pencil marking.” This involves writing down all possible numbers in each empty square before making any moves. Then use logic and elimination techniques to cross off impossible numbers until you are left with the correct answer.

Another advanced technique is “hidden pairs.” Look for two squares within a row or column that only have two possible numbers left. If those two possible numbers exist in both squares, then those two squares must contain those specific numbers.

Benefits of Solving Sudoku Puzzles

Not only is solving Sudoku puzzles fun and challenging, but it also has many benefits for your brain health. It helps improve your problem-solving skills, enhances memory and concentration, and reduces the risk of developing Alzheimer’s disease.

In conclusion, Sudoku is a great way to improve your problem-solving skills while also providing entertainment. With these starting and advanced strategies, you’ll be able to solve even the toughest Sudoku puzzles. So grab a pencil and paper and start sharpening those brain muscles.

This text was generated using a large language model, and select text has been reviewed and moderated for purposes such as readability.

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The 10 Most Popular Coding Challenge Websites [Updated for 2021]

A great way to improve your skills when learning to code is by solving coding challenges. Solving different types of challenges and puzzles can help you become a better problem solver, learn the intricacies of a programming language, prepare for job interviews, learn new algorithms, and more.

Below is a list of some popular coding challenge websites with a short description of what each one offers.

1. TopCoder

TopCoder is one of the original platforms for competitive programming online. It provides a list of algorithmic challenges from the past that you can complete on your own directly online using their code editor. Their popular Single Round Matches are offered a few times per month at a specific time where you compete against others to solve challenges the fastest with the best score.

The top ranked users on TopCoder are very good competitive programmers and regularly compete in programming competitions. The top ranked user maintains his own blog titled Algorithms weekly by Petr Mitrichev where he writes about coding competitions, algorithms, math, and more.

2. Coderbyte

Coderbyte provides 200+ coding challenges you can solve directly online in one of 10 programming languages (check out this example ). The challenges range from easy (finding the largest word in a string) to hard (print the maximum cardinality matching of a graph).

They also provide a collection of algorithm tutorials , introductory videos, and interview preparation courses . Unlike HackerRank and other similar websites, you are able to view the solutions other users provide for any challenge aside from the official solutions posted by Coderbyte.

3. Project Euler

Project Euler provides a large collection of challenges in the domain of computer science and mathematics. The challenges typically involve writing a small program to figure out the solution to a clever mathematical formula or equation, such as finding the sum of digits of all numbers preceding each number in a series.

You cannot directly code on the website in an editor, so you would need to write a solution on your own computer and then provide the solution on their website.

4. HackerRank

HackerRank provides challenges for several different domains such as Algorithms, Mathematics, SQL, Functional Programming, AI, and more. You can solve all the challenge directly online (check out this example ).

They provide a discussion and leaderboard for every challenge, and most challenges come with an editorial that explains more about the challenge and how to approach it to come up with a solution.

Currently, if you don't solve the problem, then you can't see the solution of others. If you also try to check the editorial before solving the problem, then you won't get the point for solving the problem at all.

As an example, here I haven't solved the problem, and I am trying to check others' submissions:

And here, I haven't solved the problem, and I am trying to check the editorial:

HackerRank also provides the ability for users to submit applications and apply to jobs by solving company-sponsored coding challenges.

5. CodeChef

CodeChef is an Indian-based competitive programming website that provides hundreds of challenges. You are able to write code in their online editor and view a collections of challenges that are separated into different categories depending on your skill level (check out this example ). They have a large community of coders that contribute to the forums, write tutorials , and take part in CodeChef’s coding competitions .

6. Exercism.io

Exercism is a coding challenge website that offers 3100+ challenges spanning 52 different programming languages. After picking a language that you'd like to master, you tackle the coding challenges right on your machine (Exercism has their own command line interface that you can download from GitHub).

It is a bit different from other challenge websites, however, because you work with a mentor after completing each challenge. The mentor reviews your answers online and helps you improve them if needed. Once your answers have been approved and submitted, you unlock more challenges.

7. Codewars

Codewars provides a large collection of coding challenges submitted and edited by their own community. You can solve the challenges directly online in their editor in one of several languages. You can view a discussion for each challenges as well as user solutions.

8. LeetCode

LeetCode is a popular Online Judge that provides a list of 190+ challenges that can help you prepare for technical job interviews. You can solve the challenges directly online in one of 9 programming languages. You are not able to view other users' solutions, but you are provided statistics for your own solutions such as how fast your code ran when compared to other users' code.

They also have a Mock Interview section that is specifically for job interview preparation, they host their own coding contests , and they have a section for articles to help you better understand certain problems.

Sphere Online Judge (SPOJ) is an online judge that provides over 20k coding challenges. You are able to submit your code in an online editor . SPOJ also hosts their own contests and has an area for users to discuss coding challenges. They do not currently provide any official solutions or editorials like some other websites do, though.

10. CodinGame

CodinGame is a bit different from the other websites, because instead of simply solving coding challenges in an editor, you actually take part in writing the code for games that you play directly online. You can see a list of games currently offered here and an example of one here . The game comes with a problem description, test cases, and an editor where you can write your code in one of 20+ programming languages.

Although this website is different than typical competitive programming websites such as the ones mentioned above, it is still popular amongst programmers who enjoy solving challenges and taking part in contests.

This list was based on a few things: my own experiences using the websites, some Google searches , Quora posts , and articles such as this one and this one . I also frequented some forums and subreddits such as r/learnprogramming to see what websites were usually recommended by the users there. Disclaimer: I work at Coderbyte which is one of the websites mentioned above.

CEO & Founder at Coderbyte.

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Posted on Jun 8, 2022 • Updated on Sep 15, 2022

Top 10 Coding Challenge Websites

Let's just be honest. Coding is difficult but if you have curiosity, determination, and sheer will to learn to code then you can definitely do it. Writing code is also all about problem-solving. To excel in anything you need is practice (lots and lots of practice), and coding challenge websites help you do that. A great way to improve your skills when learning to code is by solving coding challenges. Solving different types of coding challenges and puzzles can enhance your problem-solving skills, and learning the intricacies of a programming language will open the doors for better opportunities.

Here is the list of the top 10 coding challenge websites to sharpen your coding skills:

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5 Best Coding Challenge Websites In 2023

Looking to find the best coding challenge websites to improve your coding skills and land that next job? Well, look no further, because today we are going to break down the top coding platforms to improve your coding skills!

While all of these challenge sites aim to improve your algorithm & data structure skills, only a few are successful. Additionally, every coding challenge site seems to focus on different aspects that make each platform unique and useful in its own way.

As a developer trying to teach yourself how to code, it’s important to be using the right tools to make the learning process easier and faster. By understanding the benefits and drawbacks of each platform, you can be sure you are being as efficient with your time as possible.

So without further ado, let’s jump right in and discover some of the best coding challenge sites to improve your skills.

Best Coding Platforms

1. hackerrank.

Let’s start things off with one of my favorite challenge sites, HackerRank . HackerRank’s mission is to help prepare software developers for technical interviews and improve their coding skills with a series of coding challenges in major divisions of coding.

The platform has a well-defined area to teach algorithms and data structures that any self-learner would be satisfied with. What really makes HackerRank stand out, however, is that you can also learn specific programming languages and mathematic concepts as well.

You can check out all of the available subjects below:

HackerRank does a great job of connecting developers and employers through their job board, has exceptionally well-organized coding challenges, trusted high-quality free content, a realistic coding environment, and best of all, is fun to use!

If you want to learn more about HackerRank, you can check out our review here .

2. Codewars

Codewars is another one of the best coding challenge websites in 2023. The site features a ton of great challenges that will push your abilities and increase your skills as a programmer. It also features one of the largest language supports of any site on this list. Codewars supports 29 core languages and 26 additional beta languages!

A big difference between Codewars and HackerRank is that Codewars seems to focus more on building a community than HackerRank . Users are motivated to create their own challenges, monitor the site, and join clans. The site basically maintains itself because of the members that use it.

If you are looking for a coding challenge website that focuses more on social aspects, Codewars is probably the coding site for you.

You can check out our full review of Codewars here .

3. LeetCode

LeetCode is the golden standard for technical interviews and our favorite coding challenge site for landing your next job. We found that LeetCode’s thousands of free challenges were the best laid out of all the sites on this list. It features a tagging system that makes it easy to practice algorithmic challenges related to each other and the description of the challenges is also very easy to understand.

In addition, they have lists of the most popular tech interview questions on their site. Including questions asked at top tech companies like Google, Facebook, Amazon, and Microsoft.

Comparing LeetCode to Codewars , it’s obvious that LeetCode lacks the social aspect you may find in Codewars. However, if you want a no-nonsense coding challenge site to improve your skills, look no further than LeetCode!

4. CodeChef

If competitive programming is your style, CodeChef is the coding platform for you! Among the typical algorithmic challenges you’ll find on all of these sites, CodeChef also offers many coding competitions. You can find the most recent challenges to show off your skills here .

Competitive coding aside, there isn’t much at CodeChef that you can’t find a better version of in the coding sites above. While CodeChef will certainly improve your coding skills, if you aren’t looking for competitive coding, you may be wasting your time with CodeChef.

If you want to learn more about CodeChef, check out our review here .

CheckIO gives an interesting approach to coding challenge platforms. Instead of setting out a list of coding challenges laid out by a tag system, CheckIO treats learning how to code like a game!

CheckIO’s main purpose is to be used as supplementary material for teaching a class. For that reason, it isn’t a great option if you are preparing for an interview. However, if you want a fun, interactive way to learn how to code, CheckIO may be the right coding platform for you.

If you are a teacher it also offers an admin section that allows you to track and understand the progress of your students. A feature that is not available in any other coding platform in this list!

It’s a cool approach and we recommend you check out the full CheckIO review here .

Wrapping Up

As you can see, there are a ton of great options available to you in the realm of code challenge sites. Some of these are better geared towards nailing your coding interviews, while others are focused more on social community, learning languages, or competitive programming. Which coding site will you choose to improve your coding skills?

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Grant is a full-stack / frontend software developer passionate about writing & coding. He has many years experience working in the tech industry both as a freelancer and as an employee.

The Code Bytes is all about providing people with honest information about programming. To learn more about Grant, read his about page!

If you’re interested in freelance coding / writing services or want to partner with The Code Bytes, you can get in touch with me here!

Habiba's Little Corner

10+ Coding Challenge Websites to improve problem-solving skills, logic and creativity

Table of contents

Introduction, project euler.

Coding challenges are essential to programming, as they help developers improve their problem-solving skills, logic, and creativity. Participating in coding challenges is a great way to improve your programming skills, learn new approaches, and showcase your talent to potential employers. These websites are useful for everybody, whether you are new to coding challenges or a professional programmer. Below is a list of some popular coding challenge websites with a short description of what each one offers.

they are like Duolingo for learning to code. When learning to code, most people get stuck on the "bridge" between memorizing syntax and understanding the logic that makes it all work. Most beginners jump from memorizing syntax directly into making stuff (or trying) without fully understanding how syntax is used to solve problems. In other words, they haven't learned how to think like a programmer, yet they're trying to solve problems like a programmer. Edabit was created to bridge this gap, while also making the process fun and addictive. Learn to code with 10,000+ interactive challenges. Gain XP, unlock achievements and level up. Their bite-sized challenges are a shortcut through the coding maze.

LeetCode is a popular coding challenge website that offers an extensive range of coding problems in various programming languages. The platform provides users with a rating system that helps them track their progress and compare themselves with other developers worldwide. It has a wide range of coding problems, including system design, algorithms, and data structures. You can filter the problems by the lists, difficulty levels, status, and tags.

LeetCode also offers a premium membership that provides users with additional features, including access to exclusive problems and solutions. Most importantly, LeetCode has an amazing discussion group where people talk about their problems, and solutions, how to improve their algorithms, how to improve the efficiency of their code, and so on. This is one of the most powerful features of LeetCode.

CodeWars is a coding challenge website that offers an interactive platform for developers to improve their coding skills. The platform provides coding problems called "Katas" that are categorized by difficulty level, ranging from beginner to expert. CodeWars also has a community of developers worldwide that can help you solve coding problems and provide feedback on your solutions.

CodeWars offers a ranking system that helps you track your progress and compare yourself with other developers worldwide. The website also has a leaderboard that shows the top-performing developers on the platform. This feature can be an excellent motivator for developers looking to improve their ranking and stand out on the leaderboard.

Beecrowd is perfect for those who have just started solving coding challenges and are looking for a beginner-friendly website. On this website, you can also take part in different programming contests, and check your ranking. Also, you can check your progress, how many days have passed after signing up, how many problems you have solved, how many points you have got, and more.

HackerRank is one of the most popular coding challenge websites, providing a platform for developers to practice coding skills and compete with other developers worldwide. The website offers coding challenges in various programming languages, including C++, Java, Python, and more. HackerRank also provides a job search portal where recruiters can connect with talented developers.

HackerRank has a vast library of coding challenges that cover a wide range of topics, including algorithms, data structures, artificial intelligence, and more. The platform provides users with a ranking system which can be an excellent motivator for developers to keep improving their coding skills.

HackerRank also offers certification exams that can be taken to demonstrate your coding skills to potential employers. The platform provides certifications in various programming languages, including Python, Java, C++, and more. These certifications can be an excellent addition to your resume and can help you stand out in a crowded job market.

Kaggle is an online community platform for data scientists and machine learning enthusiasts. Also, if you are interested in data science, but don't know where to start, Kaggle has got you covered. You can check their learning section where they have many free courses which will teach you a lot of stuff from the beginning. Kaggle offers a no-setup, customizable, Jupyter Notebooks environment. Access GPUs at no cost to you and a huge repository of community-published data & code.

CodeChef is another popular website where you can solve a lot of problems, take part in contests, and so on. You can filter the problems based on different categories and solve them using any of the most popular programming languages. This website also provides user ranking including the global ranking and country-wide ranking.

They also have a learning section on their website where you can learn how to solve super helpful problems, especially for beginners. In their learning section, you can choose self-learning, mentored learning, and doubt support. Some of them are free, but in some courses, you have to pay to start them.

Topcoder is a crowdsourcing company with an open global community of designers, developers, data scientists, and competitive programmers. Topcoder pays community members for their work on projects and sells community services to corporate, mid-size, and small-business clients.

Here you can earn, learn, and do a lot more in their MVP program. For earning, you can participate in five different tracks, become a copilot, become a reviewer, and also get a freelance contract gig through Topcoder Gig Work .

Coderbyte has a vast collection of problems that you can solve. The coding challenges range in difficulty and can all be completed straight in our online editor. Coderbyte is built to help you practice programming and improve your coding skills. They offer a collection of code challenges and web development courses that can help you prepare for upcoming job interviews. They also offer a challenging library, starter courses, interview kits, and career resources. To get all the features, you need to buy a subscription plan from them.

Project Euler is a great website for solving mathematical challenging problems. The problems range in difficulty, solving one problem will expose you to a new concept that allows you to undertake a previously inaccessible problem. So the determined participant will slowly but surely work through every problem.

In CodinGame, you can improve your coding skills with fun exercises in more than 25 programming languages. It is a good website for intermediate and advanced software engineers to have fun while continuing to keep their skills sharp. Also, the challenges are gamified, and the multiplayer access means that users can challenge friends and coworkers.

Competitive programmers participate in programming contests and solve many problems on this website. Toph is where programmers participate in programming contests, solve algorithm and data structure challenges and become a part of a great community. You can solve problems in different categories on this website, and they also provide rankings based on your performance in the programming contests. If you are a beginner in problem-solving, this website can help you start your problem-solving journey.

You can develop your programming fluency in 67 different programming languages with their unique blend of learning, practice and mentoring. Exercism is free of cost and is an independent, community-funded, not-for-profit organization. Get better at programming through fun coding exercises that build your understanding of concepts. Not quite sure how well you've done? Get automated analysis on your code to get quick feedback.

Solving different types of challenges and puzzles can help you become a better problem solver, learn the intricacies of a programming language, prepare for job interviews, learn new algorithms, and more. Start participating in coding challenges today and elevate your programming skills to the next level.

Thank you for your time. I hope you found it useful. ❤️

If you enjoyed this article and want to be the first to know when I post a new one, you can follow me on Twitter @habibawael02 or here at Habiba Wael . I can't wait to know your favourite website and feel free to add any other website you know about that I may have missed.

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The 5 Best Coding Challenge Sites

Discover the 5 best coding challenge sites to apply your knowledge, solve problems, and learn from your mistakes.

November 20, 2023 by Codemotion

When Ali Partovi, Iranian-American entrepreneur, predicted a few years ago that “ Programming will become the new literacy ,” he was right. The founder of Code.org knew from firsthand experience that programming is a fundamental skill in today’s world, and one of the best ways to improve your skills in this field is through programming challenges.

These challenges allow you to apply your knowledge, solve problems, and learn from your mistakes. Fortunately, there are several websites that offer a wide range of programming challenges for developers of all levels. In this article, we present the 5 best coding challenge sites to test your skills.

LeetCode LeetCode is a coding challenge site that offers a wide range of programming problems, from basic exercises to difficult problems. The problems are categorized based on difficulty, programming language, and domain.

The site is renowned for focusing on specific problems that often arise during technical interviews. It offers a vast collection of algorithmic problems and data structure problems, with an active community discussing optimal solutions. The platform is ideal for those looking to sharpen their skills in preparation for interviews at technology companies. In fact, its problems are often used by tech companies to assess candidates during the hiring process.

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Undoubtedly, it is one of the most popular coding challenge sites globally. Therefore, it is an excellent way to prepare for coding assessments at technology companies. Its problems are challenging and realistic, helping developers improve their problem-solving abilities.

HackerRank HackerRank is another very popular coding challenge site. It offers a variety of challenges, including programming problems, algorithms, and data structures. The problems are categorized based on difficulty, programming language, and domain.

HackerRank is a coding challenge platform that stands out for its wide range of problems, covering topics from algorithms to database basics. What makes it unique is its approach to interview preparation, with simulated interviews and real-time competitions . Its diverse content and the ability to connect with others through challenges make it ideal for anyone looking to comprehensively improve their programming skills.

It offers a series of challenges designed to assess candidates’ skills in various areas, including logic, programming, and problem-solving.

Among coding challenge sites, this represents a good way to enhance technical skills and prepare for coding assessments. Its challenges are demanding and stimulating, helping developers grow professionally.

Codewars Codewars is a coding challenge site that focuses on creative coding problem-solving. The problems are categorized based on difficulty, programming language, and domain.

This coding challenge platform stands out for its interactive approach and community-driven nature. On Codewars, developers tackle “kata,” small programming exercises, to improve their skills. What makes Codewars unique is the concept of “kata,” each representing a programming problem of varying complexity. Users can solve katas and earn “kyu” or “dan” based on difficulty.

The platform also encourages clean code and collaboration through user-proposed kata solutions. This creates an interactive and social learning environment where developers can learn from others and continuously improve. Codewars is worth a try for those seeking a fun and engaging approach to sharpen their programming skills, with the opportunity to belong to a lively community of developers.

Its problems are designed to challenge developers to think outside the box and develop their critical thinking.

To develop problem-solving skills, Codewars is certainly an important ally. Its problems are stimulating and fun, helping developers grow professionally.

Recommended Article: Phind vs ChatGPT: Who Can Code Better?

Codility Codility is a coding challenge site that focuses on evaluating candidates’ skills for software development roles. Codility offers a series of challenges designed to assess candidates’ skills in various areas, including logic, programming, and problem-solving.

The programming skills assessment platform relies on code tests and programming competitions. Its main difference from other similar sites lies in its approach oriented towards evaluating developers’ technical abilities. Companies use it to assess candidates’ programming skills during the hiring process.

It offers a variety of algorithmic and coding problems covering different difficulty levels. What sets Codility apart is its practical application in corporate selection stages, allowing companies to directly assess candidates’ programming skills in a simulated test environment.

It uses a proprietary algorithm to evaluate candidates’ performance. This is designed to be as accurate as possible in assessing candidates’ skills.

An excellent way to demonstrate technical skills to potential employers. Its algorithm can help developers gain a competitive advantage in the hiring process.

HackerEarth HackerEarth is a coding challenge site that offers a variety of challenges, including programming problems, algorithms, and data structures. The problems are categorized based on difficulty, programming language, and domain.

The programming skills assessment platform is supported by a very active and lively community of developers. It offers programming challenges, hackathons, and coding competitions to help developers improve their skills.

What makes HackerEarth unique is its focus on business solutions and integration with the hiring process. Companies use HackerEarth to assess candidates’ technical skills, facilitating the connection between developers and job opportunities . The platform also hosts themed hackathons, allowing developers to solve real-world problems.

To prepare for coding assessments at technology companies, practicing with HackerEarth is an excellent way to sharpen your knowledge. Its challenges are realistic and can help developers feel more confident during the hiring process.

Conclusion In conclusion, the widespread availability of coding challenge platforms offers developers an extraordinary opportunity to improve their skills and tackle new challenges. From algorithmic challenges to interview simulations, these sites offer an interactive and engaging environment that goes beyond mere theoretical learning.

Each of the five mentioned sites—HackerEarth, LeetCode, Codility, Codewars, and HackerRank—has unique features that make them attractive to different types of developers. Choosing the right platform depends on individual needs and career goals. In any case, investing time in these resources represents a significant step toward improving programming skills and preparing for more complex challenges in the vast world of software development.

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