Category Archives: computer science

The mathematics behind the solution for Challenge No. 5

Posted on February 26, 2010 by lorg

If you take a look at the various solutions people proposed for the last challenge of generating a specific permutation, you’ll see that they are very similar. Most of them are based on some form of div-mod usage. The reason … Continue reading →

Share|
Posted in Challenges, computer science, Programming, Python | Tagged , , , , | Leave a comment

Small Programming Challenge no. 5 – Generating a Permutation

Posted on November 11, 2009 by lorg

I thought of this one quite a long time ago, and I believe that the idea behind it is pretty nice mathematically. I got the idea for it from Knuth’s “The Art of Computer Programming”. The challenge is simple: write … Continue reading →

Share|
Posted in Challenges, computer science, Programming | Tagged , | 15 Comments

10 Python Optimization Tips and Issues

Posted on September 21, 2009 by lorg

Following my previous post on Optimizing Javascript, I thought I’d write a similar post regarding Python optimization.

Share|
Posted in computer science, Design, Optimization, Programming, Python | Tagged , , , , | 7 Comments

My solution to the counting sets challenge

Posted on September 7, 2009 by lorg

A few days ago, I wrote up a challenge – to count the number of sets a given set is contained in. In the comments, I touched briefly on the original problem from which the challenge was created, and I’ll … Continue reading →

Share|
Posted in Challenges, computer science, Python | Tagged , , , | 5 Comments

Fractals in 10 minutes No. 6: Turtle Snowflake

Posted on August 31, 2009 by lorg

I didn’t write this one, but I found it’s simplicity and availability so compelling, I couldn’t just not write about it. In a reddit post from a while ago, some commenter named jfedor left the following comment: A little known … Continue reading →

Share|
Posted in computer science, Fractals, Python | Tagged , , | 4 Comments

Small Python Challenge No. 4 – Counting Sets

Posted on August 28, 2009 by lorg

This is a problem that I encountered a short while ago. It seems like it could be easily solved very efficiently, but it’s not as easy as it looks. Let’s say that we are given N (finite) sets of integers … Continue reading →

Share|
Posted in Challenges, computer science | Tagged , , | 17 Comments

Computing Large Determinants in Python

Posted on March 25, 2009 by lorg

Story: For my seminar work, I had to calculate the determinant of a large integer matrix. In this case, large meant n>=500. You might say that this isn’t very large and I would agree. However, it is large enough to … Continue reading →

Share|
Posted in Algorithms, computer science, Math, Programming, Python, Research | Tagged , , , , , | 2 Comments

Fractal Memory Usage and a Big Number

Posted on June 12, 2008 by admin

In a previous post I said I’d talk about 4**(4**(4**4)). First, about the number. I first saw it mentioned in a math lesson back in high-school, when the teacher wanted to demonstrate estimation abilities. He wrote it on the board, … Continue reading →

Share|
Posted in Algorithms, computer science, Fractals, Math, Programming, Python | Tagged , , , | 1 Comment

Issues in Writing a VM – Part 2

Posted on March 28, 2008 by lorg

Writing a VM capable of executing expression trees is different from writing a VM for executing assembly instructions. Here I’ll cover several issues stemming from this difference. The first group of issues involve generality. Supporting a specific instruction set is … Continue reading →

Share|
Posted in Algorithms, Assembly, computer science, Programming, Projects, Python | Tagged , , , , , | 7 Comments

Issues in writing a VM – Part 1

Posted on March 18, 2008 by lorg

Arkon and I decided to write a VM for vial. First though, a short explanation on what is vial: vial is a project aimed at writing a general disassembler that outputs expression trees instead of text. On top of vial, … Continue reading →

Share|
Posted in Assembly, computer science, Programming, Projects, Testing | Tagged , , , , , , | Leave a comment