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Mathematic Constraint Deduction

By barneyb on March 27, 2009

I did  Project Euler's problem 63 last night, and it was a good one:
The 5-digit number, 16807 = 7^5, is also a fifth power. Similarly, the 9-digit number, 134217728 = 8^9, is a ninth power.
How many n-digit positive integers exist which are also an nth power?
I love this sort of problem.  The algorithm for a [...]

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Project Euler Test Harness

By barneyb on March 5, 2009

Project Euler is a collection of mathematics/computer science problems, as you probably already know.  I've solved almost 50 of them so far, and I've developd a collection of utilities to make my job easier.  Some of them (factorization routines, prime generators, etc.) I'm not going to share as they are fundamental to solving certain problems.  [...]

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A Groovy Letdown

By barneyb on March 2, 2009

I'm a huge fan of Groovy, but it's major downside drove over me like a bus this evening.  What's that, you say?  Performance, of course.  Runtime "stuff" necessarily happens at runtime, and therefore affects performance.  Does this matter in most cases?  No, absolutely not.  In general it's far cheaper to buy hardware than to employ [...]

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Public Project Euler Dashboards

By barneyb on February 20, 2009

Project Euler doesn't support any kind of public stats for users, which is kind of lame I thought.  I posted about it on the Project forum and got no response, so I built my own: http://barneyb.com/projecteuler/.  The code is a total hack, faking a login to grab the protected profile page and then doing some [...]

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Prime Factorization

By barneyb on February 5, 2009

In my ongoing rampage through the Project Euler problems I've needed a prime factorization routine several times, and figured I'd share it as a complement to the sieve I shared last week.  Implemented in Groovy, of course.  Typing is a little strange on first glimpse because Groovy uses Integer by default which only supports values [...]

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Project Euler

By barneyb on February 5, 2009

In the comments to my post about my prime sieve from last week, Duncan pointed me to Project Euler, which is a collection of math problems that you can solve.  Not sure if it makes me crazy that I think it's really cool, but I do.  Even better, once you solve a problem, you gain [...]

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