In the current article I will try to solve a problem for calculation of average distance with Dijkstra, given in codeforces.com contest here in pdf. What is the problem like? We have n weighted graphs like this: For each given graph,…
Month: July 2015
C# – Enable Migrations in Visual Studio using Entity Framework
This article is rather small, but its target is to remind me how to enable migrations of database in Visual Studio. Thus, the steps are: Press Ctrl + Q to go to the quick launch. In the quick launch write…
Python Algorithms – Maximum combinations of coins
Sometimes complicated algorithms are really easy to be written down. The current problem is solved in 6 lines of code (from line 5 to line 11), but it you need to put effort to understand how the algorithm works and what are…
Python Algorithms – Full Dijkstra is stunning again
Yesterday I have spent some hours, trying to resolve one problem for shortest paths. The problem was coming from HackBulgaria and was somehow similar to these two problems here: Get the shortest path in a weighted graph with Dijkstra Dijkstra for…
Tagged with: dijkstra, dijkstra algo, dijkstra going a little crazy, Python, python algorithm dijkstra
Python – Get the shortest path in a weighted graph – Dijkstra
Today, I will take a look at a problem, similar to the one here. In the article there, I produced a matrix, calculating the cheapest plane tickets between any two airports given. Today, the task is a little different. I would…
Review – Pivot Tables Smart Data Analysis
Although I have started to learn new stuff lately, such as Python and SQL server, I am still interested in MS Excel and whatever is being published on the subject. I have noticed that the book “Pivot Tables Smart Data…
Python – Calculating words in matrix – contest problem
Today I was looking into the following problem for word counter in python from Hack Bulgaria: You are given a rectangular table filled with characters and a word. Your task is to count the occurrences of the word in the…
Python – Dijkstra algorithm for all nodes
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…
SQL Server – Solution of the first part of the SoftUni Exam for SQL Server
Just a day ago I have participated at an exam, organized from SoftUni for SQL server. The exam can be found here and the questions for it are here. In the current article I will present my answers from the first part…
Review – 11 incredible Excel conditional Formatting Tricks, Excel Shortcuts, 7 Genius ways of using Advance Filter
Today I have received something, that at first looked as a spam e-mail, but for some reason the spam filter has not caught it. Then I took a second look at it and I have noticed, that it was from…
Python – two solutions in codeforces.com
Yesterday, I have decided to make an account in codeforeces.com and to check how the system works. Pretty much quite well, in 90 minutes I have managed to solve 2 of the 5 problems: I have decided to stop, because for…
Python – Usage of a Binary Tree with List in Python
After the article here, concerning the building of the binary trees and their usefulness, today I will show how to use these trees in action 🙂 Imagine that we have the following problem, used in arena.hackbulgaria.com: Implement a program in…
Tagged with: binary list usage, binary tree list, binary tree list in python, Python, range minimal query
Python – Build a binary tree list in python
Binary trees are really useful, if you are solving an algorithmic problem. They consists of nodes (a.k.a vertices) and edges. Thus, each node has two edges, which are leading to another node. Something like this: The above tree is a simple random non-balanced…
SQL Server – Create two tables with primary and foreign key with SQL code
There is a simple way in VBA and in Python to create tables in the database you need, giving the tables a name of a variable and the type of a variable. In SQL Server, we also have a way…
SQL Server – Get data below the avarage; Difference between Left and Right Join Explained
I have started to explain tricks with SQL Server in a series of articles about a week or two ago. Today I will use a database, mentioned in a previous article. Get data below average The task is to get top…
Review – Wing IDE
Some two weeks ago, I was coding in Python with Notepad++ as a text editor and I was getting really tired, because the program was not running the way I wanted it and I had to print a lot of…
Tagged with: wing ide review
SQL Server – Conditional Query And Multiple Tables Join (Many to Many Query)
As I have already started some time ago with SQL Server, in this article I will present the way to write a if-else case in sql query. The database is available here, I have used a sample DB for one…
SQL Server – Simple Transaction in SQL Server
So, after starting with SQL Server custom views, SQL Server Triggers, SQL Server Procedures and Functions, now it is time to pay some attention to SQL Transaction as well. What are transactions? Microsoft says the following: A transaction is a single…
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