In our previous article, we explored the A* (A-Star) Algorithm. It is the gold standard for pathfinding as it is optimal – it always finds the shortest path. But in the real world (chess engines, LLM) it might be too …
In the previous articles, we have presented graphs with BFS and DFS. The BFS is actually good to find the path with the fewest nodes. But if the path with the fewest nodes is actually the most expensive, then we …
Greedy algorithm is described as an algorithm that follows the problem-solving heuristic of making the locally optimal choice at each stage with the intent of finding a global optimum. Thus, it is always interesting to find a problem, which can …
Codeforces has introduced a third division in their competitions. Initially I though this is the place to go for “easy” stuff, as far as some of the 2nd division problems require some advanced algorithms, like combinations of graphs and months …
Python – Binary String Minimizing Problem – CodeForces Read more »
The birthday paradox is an interesting problem, mainly because of its somehow “unexpected” results. The problem usually is stated as the following: What is the minimum number of people in a room, in order to have a probability higher than …
After writing about the longest palindromic substring, now it is time to see the longest palindromic subsequence. What is the difference? Pretty much, if we take the word abracadabra: the longest substring is ada in abracadabra the longest subsequence is …
VBA – Longest Palindromic Subsequence Algorithm with Excel – GIF Read more »
Another SoftUni algorithm problem that I have considered interesting is presented here: You are given an integer S. Generate all non-empty sequences of numbers in range [1…S], which have sum of elements ≤ S. Display the sequences in their natural order, …
Some days ago I was checking the algorithm problems for the algorith exam preparation of SoftUni and I have decided to solve one problem. The problem is named “Bridges” (hence the youtube link above) and is a nice example of Greed …
Having two TVs is great. Or it used to be in the 90s. Anyhow, the latest problem in CodeForces that I have resolved was concerning a guy with a schedule of TV shows, which he was planning to watch on his …
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 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 »
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 »
The Codeforces contests are sometimes more challenging than expected, even for the first problems, which are supposed to be trivial. Well, they are not that trivial. In the 762. edition, the 1. problem was concerning the n-th divisor of an …
C# – Algorithms – Find n-th divisor of an integer Read more »
As mentioned some times ago, whenever I am looking for a subject to post, the easiest way is to go to Codeforces.com and simply take a problem from the second division. If I manage to solve it from the first …
C# – Algorithms – Arpa’s hard exam and Mehrdad’s naive cheat Read more »
CodeForces.com is really a nice place you can learn stuff. Learning by doing is probably what man actually needs in programming. Thus, I have taken the 2. Problem of the 2. Division in CodeForces, as far as it seemed interesting …
This Wednesday on 18:35 I did not have anything better to do than competing in codeforces.com. I have just finished work at 18:00 and I managed to get home before the start of the competition and even to get a sandwich …
C# – Algorithms – Bear And Finding Criminals (from CodeForces) Read more »
I have not solved algorithm problems in a while and thus, I have decided to take a look at the latest not difficult problems Codeforces.Com. I somehow liked the problem for Vasya And String as far as it seemed quite easy …
In this article I will present the solution of a problem for finding the shortest path on a weighted graph, using the Dijkstra algorithm for all nodes. The problem is formulated by HackBulgaria here. Pretty much, you are given a …
Today, after playing some interesting board games, I was wondering about some probabilities with dice. As far as I did not want to calculate them with statistics methods (and it is always funnier to make a simulation), I have …
Python – Times the dice is same as previous or next Read more »