Wikipedia says that the activity selection problem is a combinatorial optimization problem concerning the selection of non-conflicting activities to perform within a given time frame, given a set of activities each marked by a start time (si) and finish time (fi). The problem is to select the maximum …
Codeforces has easy and tough questions. However, the easy are not always easy, but the tough are always tough. Thus, after writing the Excel article here for Sumproduct, I have decided to go a bit easy and start with the …
CodeForces has people working 24/7, trying to come up with interesting problems for the IT community. Thus, it’s always challenging to take a look at these problems and to try to solve them. The latest problem I have faced was one …
Sumifs() and Countifs() are formulas in Excel, that sum or count a range with multiple conditions. Unfortunately, these formulas do not work, when you want to refer to a closed workbook. That’s where the magic of the Sumproduct() formula comes. …
Excel – Use Sumproduct() instead of Sumifs() or Countifs() Read more →
In Excel, there are plenty of ways to calculate the differences between days. However, the NetworkDays Formula includes weekends and may include the holidays, which would be different for each country/province. Thus, it is useful! Here is how to use …
Business Intelligence is really a thing in the small companies – usually they do not want to invest a lot into software and consultancy, thus a regular controller or a developer can become the company’s champion easily. 🙂 As far …
News – Book Review – BI Tools for Small Companies – Coming Soon Read more →
It does not happen a lot, but this time the 2. problem of CodeForces really made me rethink my life choices and made me feel a bit sorry that I was in a school where we studied Maths about 4 hours …
CodeForces is a nice website for anyone, who likes checking himself vs the top developers worldwide. It’s even separated into divisions, thus, they kindly provide 3 easy questions and 5 hard. Although, I do not know anyone who can call …
C# – CodeForces – Okabe and Future Gadget Laboratory Read more →
Karen and Game is the third article about Karen. In a row. Pretty much, someone in CodeForces has created 7 different problems with her, thus the Japanese lady is getting famous. This time the problem looks like this: The game is …
If you are following this blog you are probably asking yourself Who the beep is Karen? and why do I write a 2. article about her in a row? 🙂 Well, that’s Karen and she obviously likes coffee: Karen was the main …
Its Sunday and it is time for CodeForces. Today I have taken a look at round number 816, Problem A. The problem initially looks rather easy and you think that nothing can go wrong, until you do not try it. …
The past week, on Monday and Tuesday I was in Berlin, for the DevOpsCon. On Tuesday was the first day of the conference. I was present on a few DevOps talks and in general, I managed to understand …
News – DevOpsCon – What has VitoshAcademy done 2 days in Berlin? Read more →
CodeForces.com is a web site for competitive programming. One of the 2 really famous sites in internet. Yesterday I was fighting with a the problem 2 in Division B from competition number 814 for about 1 hour, until I have managed …
CodeFoces.com is the place where I go when I do not know what to blog about. 🙂 Anyhow, as a developer who is with some experience there, I always expect that the first problems of Division 2 would be quite …
C# – CodeForces – An abandoned sentiment from past Read more →
In less than 4 days I would be travelling to Berlin to see what is happening on the DevOpsCon there. I will be present for a whole day workshop for machine learning with Python, thus I have decided that it …
DevOps Conference in coming – time to install Python on my machine Read more →
Codeforces.com is the web site, that lets you check your algorithmic skills, in case that you want to see where you are, compared to the world. Thus, today I was checking the problems in the 2. Division and the first …
After the first two videos for C# Entity Framework (Video 1 and Video 2) I have decided to make a small one for the Code First approach. I have used the materials of SoftUni here, mainly concentrating on problem 3. …
After the first part of the SoftUni homework for Entity Framework here, I have decided to make a small video with the next 4 problems. Following the same logic, I have made a 30 minute YouTube video with the trial …
Entity Framework – C# – Introduction – Video – Part 2 Read more →
I have started some time ago to do stuff with Entity Framework (EF) in VitoshAcademy, I even have two articles about it – Beginning with EF and Enable Migrations with EF. I have noticed that the SoftUni is having an EF course, …
Wikipedia says the following for the Knight’s tour : A knight’s tour is a sequence of moves of a knight on a chessboard such that the knight visits every square only once. If the knight ends on a square that is …
This week was a nice one in a way – no work and just conferencing in Munich! The .Net Summit in Munich has gathered about 40 .Net professionals and “meine wenigkeit” was one of them. Thus, I have participated in …
.Net Summit – Something interesting in Munich! 🙂 Read more →
Solving problems in CodeForces usually never works out as expected somehow – if I tend to overestimate the problem, I am able to solve it within 10 minutes and if I underestimate it, I stay about 1 hour on a simple …
After reviewing the Meller watch, it’s time for some more IT related stuff in the blog. Thus, I have decided to do what I usually do when I want to write some article and I do not know what to …
Codeforces – Problem 798A – Checking the Calendar Read more →
As a blogger I review software and IT books quite a lot. Thus, I have decided to switch a bit to something else. E.g. – reviewing gadgets and anything interesting. 🙂 Thus, the first item I managed to obtain for …
Comparing the speed of VBA and C++ in general is quite not fair. Its like comparing the speed of a military jet and a Boeing 767. But still, it’s interesting to see how much C++ is faster in Excel’s native …
VBA vs C++ function – which one is faster in Excel? Read more →
After adding a c# library to VBA I have decided to take a look how to do a similar trick with C++. C++ is a bit fancier in a way. And it works somehow else. So, let’s start. Imagine that we …
In VitoshAcademy I try to be on the edge of VBA technologies. Unfortunately, this is not that difficult, as far as VBA is really like the hated child of Microsoft – it works quite a lot and it does a pretty …
My friends from Apress.com have provided me again with a great book upon my request! Thus, it is time for the review. In general, I was awaiting 190 page book with Visual Studio shortcuts and quick tricks. Even, I was …
Book Review – Practical Microsoft Visual Studio 2015 Read more →
As a VBA Developer, I am always interested in the latest technologies in the VBA world. This is not that difficult, as far as there is not plenty of new stuff there, thus whenever I see something interesting, I try …
Review – vbWatchdog – professional error tracking tool Read more →
VitoshAcademy is opening new horizons! In the beginning of May, I will go to Munich, to participate in the .Net Summit and just to see where the German .Net professionals stand. The event is in Munich and is divided into …