To make test run when you issue make check, you need to add them to the TESTS variable Assuming you’ve already built the executable that runs the unit tests, you just add the name of the executable to the TESTS variable like this: TESTS=my-test-executable It should then be automatically run when you make check, and … Read more
Equal hash means equal file, unless someone malicious is messing around with your files and injecting collisions. (this could be the case if they are downloading stuff from the internet) If that is the case go for a SHA2 based function. There are no accidental MD5 collisions, 1,47×10-29 is a really really really small number. … Read more
This sounds very similar to Robocode. Robocode is a programming game, where the goal is to develop a robot battle tank to battle against other tanks in Java or .NET. The robot battles are running in real-time and on-screen.
Here is an extensive discussion. There are a lot of algorithms. A simple one is to take the LU decomposition. Then, since det M = det LU = det L * det U and both L and U are triangular, the determinant is a product of the diagonal elements of L and U. That is … Read more
Use &&/AND/and, not ||/OR/or: v != “x” && v != “y” && v != “z” Problem If an if block is always executed, the condition for the if block always evaluates to true. The logical expression must be wrong. Let us consider v != “x” || v != “y” || v != “z” for each … Read more
FMTEYEWTK about Fancy Regexes Ok, I’m going to go from the simple to the sublime. Enjoy! Simple s///e Solution Given this: #!/usr/bin/perl $_ = <<“End_of_G&S”; This particularly rapid, unintelligible patter isn’t generally heard, and if it is it doesn’t matter! End_of_G&S my $count = 0; Then this: s{ \b ( [\w’]+ ) \b }{ sprintf … Read more
There is a beautiful structure called an extendible array that has worst-case O(1) insertion and O(n) memory overhead (that is, it’s asymptotically comparable to a dynamic array, but has O(1) worst-case insertion). The trick is to take the approach that the vector uses – doubling and copying – but to make the copying lazy. For … Read more
If we are talking about OOP than the term “message passing” comes from Smalltalk. In a few words the Smalltalk basic principles are: Object is the basic unit of object-oriented system. Objects have their own state. Objects communicate by sending and receiving messages. If you are interested in Smalltalk take a look at Pharo or … Read more
Let’s assume you want to draw an N-sided polygon of radius r, centred at (0,0). Then the n vertices are given by: x[n] = r * cos(2*pi*n/N) y[n] = r * sin(2*pi*n/N) where 0 <= n < N. Note that cos and sin here are working in radians, not degrees (this is pretty common in … Read more
I normally follow one easy principle: Everything that is mandatory for the correct existence and behavior of the class instance should be passed and done into the constructor. Every other activity is done by other methods. The constructor should never: use other methods of the class with the purpose of using overriding behavior act on … Read more