The Project Euler thread

[Reincarnate]

Re: THE project euler thread

for the summation of totient? really?

yes

[stargroup100]

Re: THE project euler thread

okay I made a small improvement on the speed of computation but it's not anything significant. what the hell did you do

[Reincarnate]

Re: THE project euler thread

Try messing around with http://pari.math.u-bordeaux.fr/

[leonid]

Re: THE project euler thread

yeeeeessssshhhhh

[hondaracer600]

Re: THE project euler thread

Reincarnate

I have been lurking on this thread for a few days. I wanted to see if I could pick your brain a bit on problem 355.

I have been getting close by implementing FFR4EVA_00's method of [a_2,a_3,a_5...a_p]. It is basically bumping the exponent of all primes < N

But alas, the answer is incorrect.

Did you use a method like this? Or did you go down a different path?

[stargroup100]

Re: THE project euler thread

You have to do a lot more with that because the method for checking optimization possibilities from there is much too broad and will take forever.

If you try to optimize that you'll be doing well over 10^(300+) calculations, which your program will not finish within the lifespan of the universe.

[Reincarnate]

Re: THE project euler thread

Reincarnate

I have been lurking on this thread for a few days. I wanted to see if I could pick your brain a bit on problem 355.

I have been getting close by implementing FFR4EVA_00's method of [a_2,a_3,a_5...a_p]. It is basically bumping the exponent of all primes < N

But alas, the answer is incorrect.

Did you use a method like this? Or did you go down a different path?

Raising the exponents of the initial "<N" prime list is just a starting point -- from there you need to create prime composites that you can add into the list. Just a matter of determining which composites are worth adding and which are useless. Some of them will be ambiguous -- which is what was tripping me up for the better part of 1.5 days. I ultimately had to do that part manually. I'm not sure if FFR4EVA had a fully automated solution or not, but mine wasn't.

[stargroup100]

Re: THE project euler thread

holy crap pari/gp lololol

this thing rules lololololololol

****in hell

[hondaracer600]

Re: THE project euler thread

Raising the exponents of the initial "<N" prime list is just a starting point -- from there you need to create prime composites that you can add into the list. Just a matter of determining which composites are worth adding and which are useless. Some of them will be ambiguous -- which is what was tripping me up for the better part of 1.5 days. I ultimately had to do that part manually. I'm not sure if FFR4EVA had a fully automated solution or not, but mine wasn't.

Define "Manually". Are we talking pen and pad here?

[stargroup100]

Re: THE project euler thread

Yes, the four of us that solved it all did the last part manually.

[Reincarnate]

Re: THE project euler thread

Solved 190 with Excel... <3

[hondaracer600]

Re: THE project euler thread

Solved 190 with Excel... <3

Wow you guys really are gods among men. What is your education? I am working on a MS in CS.

I am working on the < 100 problems. My Advanced Algorithms teacher is giving a massive amount of extra credit if you can show you solved one of them.

I am using the 3 conjectures and the way FFREVA started to get a pretty good start, but I am still falling short.

[stargroup100]

Re: THE project euler thread

Undergraduate sophomore. Took a basic course in programming and that's it.

Honestly, I just love Project Euler problems because you don't need to be super crazy good at programming to solve them, as long as you have a good sense with math.

My code for problem 355 (excluding the last part which was manual) was completely done with the most basic programming concepts and nothing else. For loops, while loops, a small handful of dedicated functions, and that's it.

[hondaracer600]

Re: THE project euler thread

Undergraduate sophomore. Took a basic course in programming and that's it.

Honestly, I just love Project Euler problems because you don't need to be super crazy good at programming to solve them, as long as you have a good sense with math.

My code for problem 355 (excluding the last part which was manual) was completely done with the most basic programming concepts and nothing else. For loops, while loops, a small handful of dedicated functions, and that's it.

Where did the pen and pad come in? I find it hard that in ~18k elements, your pen is going to make a difference.

[Reincarnate]

Re: THE project euler thread

There is no literal pen and pad needed -- just some manual fudging to the program

EDIT: Solved all the triangle-numbered problems



Almost got 354 solved... just one piece missing but I'm too tired to fiddle with it tonight. night yall