I am starting weekly updates to share what I learn, read, build, and ship. Alongside technical articles, these posts will include books, personal projects, and reflections on work and everyday life.

Why Start Weekly Blog Updates?

I shared my first blog in December 2019. Back then, the intention was only to share posts about technical topics, and I’ve shared a couple of blogs, mostly related to competitive programming.

Recently, I decided to make a shift in what I post. I want to share about different topics: some might be purely technical, others might be opinion-based, I might write about a book I’ve read, or how I think about AI affecting life, society, and work.

Read more →

This n8n workflow tracks students’ competitive programming progress by connecting the Codeforces API to Google Sheets. I walk through fetching submissions, calculating metrics, handling API errors, and updating the sheet.

Why Automate Codeforces Progress Tracking?

Recently, I started exploring workflow automation tools because I wanted to automate some tasks that I perform regularly. After a short search, I came across several options, including Zapier, Make, and n8n.

I had a few requirements in mind: the tool should be simple to use, easy to learn, supported by an active community, and available to test for free. I had already heard a lot about n8n, and a friend of mine had recently joined the company. Since I was also looking for different career opportunities, becoming familiar with the product seemed especially worthwhile.

Everything was pointing towards n8n, so I decided to give it a try. I started by building a simple workflow before moving on to something more complex.

Read more →

Working at a software consulting company can offer varied projects and a broad professional network, alongside challenges with ownership and changing clients. Here are the trade-offs I have experienced as a software engineer.

What Is a Software Consulting Company?

A consulting company is a professional services firm that provides expert advice or specialized delivery capacity to other businesses. For example, if a company has legal issues, it may hire a law firm. If it needs help filing taxes, it may hire an accounting firm. In software development, companies hire consultants for many reasons:

• Legacy System Migrations: You have an old legacy system that is becoming impossible to maintain, so you hire a consulting company to migrate to a new codebase.
• Cloud Architecture: You have an on-premises system that you want to migrate to the cloud.
• Staff Augmentation: You need to deliver features quickly, and your internal IT department cannot handle everything, so you hire external engineers.
• Core Business Focus: You want to focus more on the marketing and business growth of your application, and you don’t want to hire and manage an engineering department.
• Other cases: You need outside expertise, temporary capacity, or an independent technical perspective.

Read more →

The proxy pattern can separate network replies from the code that processes their data. This Qt tutorial compares a signals-and-slots approach with an APIReply wrapper around QNetworkReply.

Background: Processing Network Replies in Qt

In a previous project that I worked on, we had to connect to backend API using Qt framework in order to download some files and display some content of these files, this thing might look easily done using QNetworkAccessManager and QNetworkReply. But we had other things to consider:

• Size of the downloaded files was large.
• No file should be stored in the device running the application.

Read more →

This unofficial editorial for AtCoder Beginner Contest 185 (ABC185) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

Codeforces Polygon supports the full process of creating a programming contest problem. This tutorial walks through statements, generators, validators, checkers, and tests using a sample problem and testlib.h.

What Is Codeforces Polygon?

According to Polygon itself, The mission of Polygon is to provide platform for creation of programming contest problems. Polygon supports the whole development cycle:

• Problem statement writing.
• Test data preparing (generators supported).
• Model solutions (including correct and wittingly incorrect).
• Judging.
• Automatic validation.

Read more →

This unofficial editorial for AtCoder Beginner Contest 179 (ABC179) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

This unofficial editorial for AtCoder Beginner Contest 178 (ABC178) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

Stress testing finds counterexamples by comparing a solution against a brute-force implementation on randomly generated inputs. This C++ tutorial covers test generators, comparison scripts, and custom checkers for problems with multiple valid answers.

I decided to write this article after watching the last screencast made by Errichto. To be more precise when he started making stress testing to find counter-test you can check that here. Errichto has a full video called How to test your solution in Competitive Programming, on Linux? I highly recommend you to check it, basically this article is the same but I am extending it to stress test solutions with multiple answers using a written checker, so let’s jump in.

Read more →

Autocomplete relies on data structures that can find words by prefix efficiently. This article compares tries and ternary search trees and shows how to implement both approaches in C++.

How Prefix-Based Autocomplete Works

Autocomplete is the feature when an application predicts the complete word, after just typing some prefix of the word. You must have used autocomplete feature a lot in your life in many area like:

• Search engines, Google search engine suggests to you an autocomplete feature when you type some text in the search bar, usually sorted by most trends.
• Emails, as you start writing some prefix of the Email address you will get a list of suggestions.
• Social media, like facebook, linkedin, instagram…
• In source code editors, actually I am using Atom right now and I have used autocomplete for at least 10 times just in the first small part of this article.

Read more →

Combinatorial game theory helps determine whether a player can force a win. This tutorial introduces winning and losing positions, Nim, and the Sprague-Grundy theorem through competitive programming examples.

Combinatorial Games

The game is said to be Combinatorial if it satisfies the following conditions:

1. The game is played between two players, we will call them Alice and Bob.
2. The two players alternate playing, Alice plays first.
3. We can define two sets \(F_1\) and \(F_2\) of possible moves for each player, these sets are usually finite, based on these two sets we can classify combinatorial games into:
   • Combinatorial impartial games this happens when \(F_1 = F_2\), this means both players have the same options of moving from each position.
   • Combinatorial partizan games this happens when \(F_1\ne F_2\), this includes games like chess or checkers in which one player moves the white pieces, and the other player moves the black pieces.
4. There is an end position of the game, usually called the terminal position. In normal play rule the player making the last move wins the game, in misère play rules the player making the last move loses the game.
5. The game always ends after some finite number of moves.

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This tutorial connects maximum independent sets, minimum vertex covers, and maximum matching in bipartite graphs. It explains the ideas and implements matching with max flow and augmenting paths in C++.

Introduction to Independent Sets

The title contains a lot of terms that should be explained separately before we start, given an undirected graph \(G = (V, E)\) we define the following terms:

• Independent Set (IS) : Subset of nodes \(U \subseteq V\) with the following propriety: For any two nodes \(u, v \in U\) nodes \(u, v\) are not adjacent ( There is no direct edge between nodes \(u\) and \(v\) ).
• Maximal Independent Set (MIS) : An independent set is maximal if no node can be added to it without violating the independence condition.
• Maximum Independent Set (MaxIS) : An independent set of maximum cardinality.

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A monotonic queue finds the minimum in each sliding window in linear time. This tutorial develops a C++ implementation and extends it to minimums in two-dimensional submatrices.

Sliding Window Minimum: The Motivation Problem

Given \(n \times m\) matrix \((1 \le n, m \le 3*10^3)\) you have to calculate the sum of minimum numbers in all sub-matrices of size \(a\times b\) with top left corners in \((i, j)\) over all \(1 \le i \le n-a+1\) and \(1 \le j \le m-b+1\).

Read more →

Noise in communication systems limits transmission rates and makes signals harder to decode. This article explains thermal noise, Gaussian and white noise models, and signal-to-noise ratio (SNR).

The term noise refers to unwanted electrical signal in electrical systems. This unwanted signal masks the information signal, limiting the transmission rate and affecting the receivers ability to make the correct symbol decision.

In communication systems noise arises due to different sources, these sources can be classified in two categories:

• Natural noise:
  • Atmospheric noise.
  • Noise from the sun.
  • Other galactic radiation sources.
• Man-made noise:
  • Ignition noise.
  • Radiating electromagnetic signals.

Read more →

I am starting weekly updates to share what I learn, read, build, and ship. Alongside technical articles, these posts will include books, personal projects, and reflections on work and everyday life.

Why Start Weekly Blog Updates?

I shared my first blog in December 2019. Back then, the intention was only to share posts about technical topics, and I’ve shared a couple of blogs, mostly related to competitive programming.

Recently, I decided to make a shift in what I post. I want to share about different topics: some might be purely technical, others might be opinion-based, I might write about a book I’ve read, or how I think about AI affecting life, society, and work.

Read more →

This n8n workflow tracks students’ competitive programming progress by connecting the Codeforces API to Google Sheets. I walk through fetching submissions, calculating metrics, handling API errors, and updating the sheet.

Why Automate Codeforces Progress Tracking?

Recently, I started exploring workflow automation tools because I wanted to automate some tasks that I perform regularly. After a short search, I came across several options, including Zapier, Make, and n8n.

I had a few requirements in mind: the tool should be simple to use, easy to learn, supported by an active community, and available to test for free. I had already heard a lot about n8n, and a friend of mine had recently joined the company. Since I was also looking for different career opportunities, becoming familiar with the product seemed especially worthwhile.

Everything was pointing towards n8n, so I decided to give it a try. I started by building a simple workflow before moving on to something more complex.

Read more →

Working at a software consulting company can offer varied projects and a broad professional network, alongside challenges with ownership and changing clients. Here are the trade-offs I have experienced as a software engineer.

What Is a Software Consulting Company?

A consulting company is a professional services firm that provides expert advice or specialized delivery capacity to other businesses. For example, if a company has legal issues, it may hire a law firm. If it needs help filing taxes, it may hire an accounting firm. In software development, companies hire consultants for many reasons:

• Legacy System Migrations: You have an old legacy system that is becoming impossible to maintain, so you hire a consulting company to migrate to a new codebase.
• Cloud Architecture: You have an on-premises system that you want to migrate to the cloud.
• Staff Augmentation: You need to deliver features quickly, and your internal IT department cannot handle everything, so you hire external engineers.
• Core Business Focus: You want to focus more on the marketing and business growth of your application, and you don’t want to hire and manage an engineering department.
• Other cases: You need outside expertise, temporary capacity, or an independent technical perspective.

Read more →

The proxy pattern can separate network replies from the code that processes their data. This Qt tutorial compares a signals-and-slots approach with an APIReply wrapper around QNetworkReply.

Background: Processing Network Replies in Qt

In a previous project that I worked on, we had to connect to backend API using Qt framework in order to download some files and display some content of these files, this thing might look easily done using QNetworkAccessManager and QNetworkReply. But we had other things to consider:

• Size of the downloaded files was large.
• No file should be stored in the device running the application.

Read more →

This unofficial editorial for AtCoder Beginner Contest 185 (ABC185) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

Codeforces Polygon supports the full process of creating a programming contest problem. This tutorial walks through statements, generators, validators, checkers, and tests using a sample problem and testlib.h.

What Is Codeforces Polygon?

According to Polygon itself, The mission of Polygon is to provide platform for creation of programming contest problems. Polygon supports the whole development cycle:

• Problem statement writing.
• Test data preparing (generators supported).
• Model solutions (including correct and wittingly incorrect).
• Judging.
• Automatic validation.

Read more →

This unofficial editorial for AtCoder Beginner Contest 179 (ABC179) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

This unofficial editorial for AtCoder Beginner Contest 178 (ABC178) explains the approaches, time complexities, and C++ solutions for problems A through F.

Read more →

Stress testing finds counterexamples by comparing a solution against a brute-force implementation on randomly generated inputs. This C++ tutorial covers test generators, comparison scripts, and custom checkers for problems with multiple valid answers.

I decided to write this article after watching the last screencast made by Errichto. To be more precise when he started making stress testing to find counter-test you can check that here. Errichto has a full video called How to test your solution in Competitive Programming, on Linux? I highly recommend you to check it, basically this article is the same but I am extending it to stress test solutions with multiple answers using a written checker, so let’s jump in.

Read more →

Autocomplete relies on data structures that can find words by prefix efficiently. This article compares tries and ternary search trees and shows how to implement both approaches in C++.

How Prefix-Based Autocomplete Works

Autocomplete is the feature when an application predicts the complete word, after just typing some prefix of the word. You must have used autocomplete feature a lot in your life in many area like:

• Search engines, Google search engine suggests to you an autocomplete feature when you type some text in the search bar, usually sorted by most trends.
• Emails, as you start writing some prefix of the Email address you will get a list of suggestions.
• Social media, like facebook, linkedin, instagram…
• In source code editors, actually I am using Atom right now and I have used autocomplete for at least 10 times just in the first small part of this article.

Read more →