The Project Euler thread
 

for getting stargroup mad at people leaking answers EXCEPT NOT BECAUSE WE HAVE...

http://projecteuler.net/

what you do is simple:
1. make an account
2. open a problem
3. solve the shit out of it
4. rinse and repeat

a lot of the problems, ESPECIALLY later on, require you to find a general solution via programming and plug some ridiculously large parameters into them

anyway, i have completed:
1-13, 16, 18, 28, 33, 52, 67, 79, 108, 110, 157, 267, 355

and i am working on something...

Re: THE project euler thread
 

I've completed 3 of the puzzles so far, mostly because I have very little time to complete them. I will be going in linear order from start to finish! Using C++ as my language because I'm taking a course on it right now.

Excellent idea ffr4eva.
When people run into problems they can post their questions here, just remember to hide your solutions in spoiler tags and try not to ever post the complete solution!

Re: THE project euler thread
 

your welcome zageron for telling you about this first :3

i have 1-25, 28 and 30
And i work with java

Re: THE project euler thread
 

So far I've done 1,2,3,5 and 6. I just learned about the bigInteger type in Java so now I'll be using that (since the 'long' type isn't ****ing long enough -__-.)

Re: THE project euler thread
 

hehe, i did all them without using the bigInteger type.

I used manual math with arrays of integers

Re: THE project euler thread
 

Sounds like how the bigInteger type would be implemented. I'd rather just use that, I find no point in implementing a new data structure if one is already implemented for me to use already. :razz:

Re: THE project euler thread
 

This seems really interesting. I could try to do this on my free time to work on my computer skills.

Re: THE project euler thread
 

I'm currently at 49, using mostly Maple. I have done a couple in C++ too, where speed mattered.

I should get back into it.

Friend key is 62306152188978_1d29510ddc0c52e8c33db3cdbaf399db for interested people.

Re: THE project euler thread
 

* Working on P83 *





I'm mostly using Ruby and C

My friend key: 1858629421787_a864c4e88f44e36b8023644c0f14493e

Re: THE project euler thread
 

I just started today and got 1, 2, 3, 5, 6, 7, 9, 10, 16, 20, 25, 45, 48, and 52 solved. I'm using Mathematica here.

Friend Key: 76814575274714_b466b39d7ef7730e66d3da5b16df2525

Re: THE project euler thread
 

By the way... Friend Key: 41335338220707_9d1fa87f00c010a47b494214e8b3416e ^_^

EDIT:
I managed to do a few today, and now I have 1-10 done. ^_^


I would, but I don't know how much code I could give before giving the answer away. =/

Re: THE project euler thread
 

I was into this for a while but got bored. It's a lot of fun, though. Some of the later problems are very tricky.

Re: THE project euler thread
 

@leonid: I got an answer to #80 but I don't understand why it's not the correct answer. Can you help me figure out the problem in my code?

Just to see if there is something wrong in my code, I tried using my program to help me determine some values. Let's define the digital sum of the first 100 digits of radical n to be f(n).

Are these values correct? I chose a few test numbers just to see if my program is telling me the right digital sum. It did tell me that f(2) = 475 which was given in the problem.

f(3) = 441
f(7) = 398
f(35) = 440
f(69) = 439
f(95) = 460

Any help would be appreciated. Thanks!

Re: THE project euler thread
 

From what I can see, you seem to be rounding off your 100th decimal.

Re: THE project euler thread
 

Well... in the case of radical 2, this is the string of digits I got from my program: {141421356237309504880...}. This is including that one digit to the left of that decimal point because the sum from that digit to the 99th decimal digit is the given 475. What confuses me is this phrase: "first one hundred decimal digits". Does this include or exclude that beginning digit? If it excludes it, the sum should've been 481.

I don't think it's a rounding error because the 100th decimal digit of radical 2 is 7, which would round the 99th decimal digit up. When I created that set of digits, 2 was the last element of that set, so that doesn't seem to be the problem in my program.

Re: THE project euler thread
 

Let's take f(95). Its 100 digits are: (note my program counts backwards)



which gives a sum of 459. The 101st decimal is a 6, so if rounded up the 7, you would get to your answer of 460.

And yes the problem isn't clear, but thanks to the example, you can understand they mean to have 100 significant digits.

Re: THE project euler thread
 

hmm maybe I will get back into this

seeing leonid ahead of me is making my competitive core act up (by that I mean he could kick my ass at this shit but idgaf)


heh solved problem 68 in excel

Re: THE project euler thread
 

Thanks! I just got 80 and 69 now! :)

Re: THE project euler thread
 

I think I'm going to get started with this. Wanted to work on my programming skills. On my reading week and nobody else I know is so why not. Probably going to work in C or Perl.

Re: THE project euler thread
 

Problem 96 is solving 50 sudoku problems. I'm very tempted to cheat