Eulering
Heyyyyyyyyy, what’s up, fools?
So remember Project Euler, that site that has hundreds of programming challenge problems? Well, I haven’t had much time for it lately (blame school), but today I decided to log back in and see if there was a problem I could try. And I found one!
This is the problem:
Passcode derivation (Problem 79): A common security method used for online banking is to ask the user for three random characters from a passcode. For example, if the passcode was 531278, they may ask for the 2nd, 3rd, and 5th characters; the expected reply would be: 317.
The text file, keylog.txt, contains fifty successful login attempts.
Given that the three characters are always asked for in order, analyse the file so as to determine the shortest possible secret passcode of unknown length.
This is one that I was able to solve by hand pretty easily, but since it’s a coding challenge site, I figured I ought to give it a shot using R. It took me a bit to get my code just right (there was one particular thing I was trying to do and I couldn’t figure out how to do it in R, so I had to modify things a bit), but I finally got it right!
Anyway, I’m not going to share my code here (it’s discouraged to share solutions outside the problem forums, each of which can only be accessed once you’ve input the correct answer for a given problem), but I thought that this was a super interesting and fun question to try. It’s easy to do by hand, but in my opinion a bit harder to do with code.
If you like this type of stuff, try it out!
Also, happy birthday, mom!
Idea
I have a good idea for a project! So remember that Project Euler website I mentioned a month (or so) ago? If you don’t, it’s a website that contains several hundred programming problems geared to people using a number of different programming languages, such as C, C++, Python, Mathematica, etc.
I was thinking today that while R is a language used by a small number of members of Project Euler, a lot of the problems seem much more difficult to do in R than in the more “general” programming languages like C++ and Java and the like. Which is fine, of course, if you’re up for a “non-R” type of challenge.
However, I was thinking it would be cool to design a set of problems specifically for R—like present an R user some problem that must be solved with multiple embedded loops…or show them some graph or picture and ask them to duplicate it as best they can…or ask them to write their own code that does the same thing as one of the built-in R functions.
Stuff like that. I’ve seen lots of R books, but none quite with that design.
I know that my office mate has been wanting to learn R but says that he learns a lot better when presented with a general problem—one that might be above his actual level of knowledge with R—and then allowed to just screw around and kind of self-teach as he figures it out.
Miiiiiiiight have to make this my first project of 2015.
Woo!
Conduct of Code
OH MY GOD this looks like fun.
From the site (and in case you don’t want to click the link for whatever reason): “Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems. The motivation for starting Project Euler, and its continuation, is to provide a platform for the inquiring mind to delve into unfamiliar areas and learn new concepts in a fun and recreational context.”
The problems look fairly challenging (at least, challenging in R, which of course is my programming language of choice, I mean c’mon), but at least it will give me a good excuse to practice!
Edit: hahaha, I’ve done like five of them already. But the rest look super hard!
Eigenblogger 