Archives

Cloning objects in .NET
In an interesting project where I'm giving a hand, we need to clone objects of a number of different types, perhaps surprisingly the CLR doesn't offer a general cloning method, of course you could use MemberwiseClone() but this is a protected method, so it can be invoked only from inside the class of the object being cloned, which makes it difficult to use it in a general method, besides, MemberWiseClone() does just a shallow copy and what we really need is a deep copy.

A cool way to find out whether a number is palindromic
In this blog entry I proposed a solution to Problem 4 at Project Euler, a crucial element of the problem is to find out whether a number is a palindrome (909 is, 809 isn't), a bit out of laziness and a bit in order to reuse existing methods, I decided to verify the palindrome by converting the number into a char array and then comparing this array with its mirror version, it works but it's not really that mathematical... Dustin Campbell proposed a solution kind of similar to mine (alas, more elegant and, above that, in F#) and using the same trick of converting the number to chars, as he didn't like this part of the solution, in this new blog entry he proposes the detection of a palindrome by mirroring the number one digit at a time. A translation of his F# code to C# 3.0 could be:

New version of F# just released
In its way from research language to commercial language, Don Syme just announced that, silently, on May the 1st version 1.9.4.15 of F# was released.

Which is the ten thousand first prime?
Prime numbers have a good deal of practical applications (for example in cryptography) but let's face it, even if they would have none, they would still be the favorite toy of mathematicians. In Problem 7 of Project Euler, we are asked to find the 10001st element of the famous list, my approach was this: