It was a beautiful journey full of internet digging, searching for patterns, learning stuff, fighting with formulas on paper, making crazy observations, coming up with brilliant ideas, implementing crazy optimizations, waiting for the programs to finish, suffering when something was wrong, and so on (and each of the mentioned not once not twice took multiple hours).

It's been a couple of months since I was left with the last unsolved problem and finally I did it! I didn't give up and I obtained the answer alone, without anyone's help, like in the rest of the problems (I was using only internet sources created before the publication of the problem). I'm writing this blog because I am bursting with joy and I wanted to share it with the community. I highly recommend PE as most of the problems were definitely very high quality (and some were a real pain in the ass, but they still teach how to overcome stuff that you're uncomfortable with).

Here's a little souvenir for me:

PS I still have no clue how to do anything useful with continued fractions.

Wow!

PS. Could you solve problem H from https://mirror.codeforces.com/contest/1666 ?

I don't get if it's a sarcasm or what xd That's true that the blog has the vibe of bragging, sorry for that, I just wanted to share my happiness that it's over. I'm not insane yet and I don't think that I can solve everything or smth.

Sorry, I didn't want it to look sarcastic, it is really cool to solve all PE problems!

The problem in the link is where you potentially could do something useful with continued fractions :)

Oh, ok, sorry, I was totally lost with your message. I might give your problem a try :P

It's the curse of written word in the Internet that with the lack of facial expressions and intonation it is sometimes hard to understand the intended message properly. I guess that everybody of us went through that a few times that we didn't get a sarcasm or a joke in the Internet and were made fun of cause of that, so we are naturally suspecting some traps even where there aren't any :p

I read some theory in linguistics that emojis (and stuff like "lol" ":p" "xD") is a substitution of facial expression in text! So we should use more :)

Radewoosh, you are the first in codeforces, you completed the project, Euler,

wowOne thing you could do with continued fractions is to use them in order to run Dijkstra on rational weighted graph in near-linear time. Here you go! https://arxiv.org/abs/2311.03321

I was thinking about solving Pell's equations or stuff like that, but the paper is nice anyway.

Wait, how and why were you solving Pell's equations

withoutcontinued fractions? :smiling_face_with_tear:Reading this everytime and crying. Maybe I've used them a few times in a way which required no/minimum of understanding.

Just saying... :)

Ok, I'm sorry, it was a mistake to skip any of your blogs, it won't happen again xd

Congrats Radewoosh!

Radewoosh orz!

Congratz!

What was your favourite problem?

I don't know of Radewoosh's favorite problem, but it truly blows my mind that the process described in https://projecteuler.net/problem=566 always ends. It has to be one of my fav and most legendary problems for me even though I made 0% progress towards solving it

This one was definitely fun :D

Hard to say, so many of them were so good. I don't remember them all so well, but looking at the list I remember 499 as a one with strong "wow, that's so cool" effect.

That's very impressive, congratulations!

gg wp

Ok, fine, I will start doing Project Euler

congratulations!<3

-also may i ask, is it useful for cp? or should i do something else instead? i mean is it the best usage of time?

-what is the things i should know before start?

i hope you accept my advice but i think project euler might kind of useful since the problems are solved using tricks you will learn however i think your question is it useful for cp is kind of big i mean what is your goal is it rating in codeforces if this is the case and then open archive and solve problems above your level do you mant IOI do more olympiad problems once you have mastered basic tricks(please do not downvote me)

yes, my goal is to reach expert here (at least) so i was asking if this will help or should i focus in another topics (at least for now), also ofc i won't downvote lol i can't even get why are they doing it :3

thanks anyway<3

thanks first, i siad don't downvote me not for you exactly but for everyone becuase in so many comments where i give some advice i get downovoted especially when i was gray(check also the comment of A4n0n4 it has so many downvotes although it is very interesting advice), as for becoming specialist i think focus more on codeforces archive problems you can use https://acodedaily.com/ very interesting to practice random problems

thanks again! i was using https://c2-ladders-juol.onrender.com/ but i will try to use the above site too ..

about the downvotes,(anyone can just click it without a reason so why should we care? xD)

i think c2 ladders has some old problems you will not deal with this issue when using atcoder daily ladders, you can check out usaco guide too.

I solved approx 100 project euler problems and so far i can't say its an efficient way to learn CP. It's way more oriented towards interesting and fun (to me at least) mathematics stuff.

If you are looking towards 100% completion of a problem set that brings you progress for CP, I find CSES great. It's great at least until "advanced techniques" and "additional problems" which I didn't do yet si I can't say.

What I really liked about CSES is that it cover most of the essential topics and for each topic, the problem are mostly climbing in difficulty which each problem. It's a perfect introduction to the multiple classes of problems before you face them in contest.

okay this is really helpful, thanks a lot

i aggree with you cses is very useful i solved a bunch of problems in it and i started feeling real improvement the tricks you learn there are very amazing good starting place before you have great understanding of how to use algos then you can start practicing randomly

Hmm. I'm pretty curious to know why its getting downvoted.

Maybe you find that project euler is an efficient way to improve your CP (for people below master)? or maybe you find CSES isn't a great problemset ?

Really curious to hear a bit more than downvotes on this one, if someone can take the time :)

Congrats man!

Can you help me with a question im stuck on?

XD Of course man, show me what you got

gigachad aired Radewoosh right there...

oh damn i forgot about that lol

now i need to remember what the question was

Congrats, great achievement!

Do you have any favorite problems?

Radewoosh orz!

Eyy, nicely done, congrats!

This is cool! How helpful do you think solving Project Euler problems is for solving problems in Codeforces contests or other programming contests?

Gratz remarkable WOW Did you use any books that helped you to achieve that?or any additional resources

What was the last problem?

University exams!

You can see from https://projecteuler.net/progress=Radewoosh;show=history, it's 812.

Oh, that link is only viewable if you're a friend of the user.

I have spent more than one year non-stop thinking about problem 812 since it was released but still have no clue at all. That is really painful.

It's obscure, but the title of the problem (Dynamical Polynomials) is actually a hint!

How many years did it take you to complete them all? Also congratulations, that is no small achievement.

Wow, very cool!

So now that you've solved every problem(and can access every problem's discussion page), can you tell us if the "one-minute rule" is real?

You can definitely do every problem within one minute runtime, but:

Congrats, Radewoosh!!!

Bro really took "Gotta Catch 'Em All" too seriously

Legendary! Congrats!

Congratulations Radewoosh! Which topic would you say appealed the most to you among all Project Euler problems, in terms of problem statements and solutions, possibly separately? Separately because my experience with PE has been that there are some problems that look benign but end up being really cool and some that are the complete opposite of this description, so I was wondering whether this is true for others too, especially someone who has solved all problems.

I'm not him, but I will share some of my favourite: 851 (see top solvers), 591 (cool theory) and 677.

Edit: I have 580 solved

Will it help me improve my CP skills?

[Deleted]

Wow. One of my friend gave me that 3 and 5 question (first question of PE) for some hints. Then I started solving PE. I did only the first 4 problems. After reading your blog I will continue again.

Highest rated on Codeforces currently, and now AKed PE. Congrats Radewoosh, you're having quite an year!

Hey,

Congrats on the achievement !!

What are some of the resources that you used to refer to revisit math concepts while solving or when stuck on a problem ?

Grats!

Congrats! If one is to start Euler project what book resources would you recommend to have a chance to solve most of them? I bet I mean book positions from combinatorics, geometry, number theory, game theory, ... ? What set of skills is crucial to solve the most difficult ones?

Thanks a lot in advance for your tips and recommendations. Cheers, Pawel

I've completed Project Euler, too.

I had ~4 problems left at the time of this blog post, feeling like I would need many more years, but then I was really motivated by your completion. Congratulations and thank you!

the fact that there are problems that take months for LGMs is scary

i don't think you need to know what quasi-modular forms or dirichlet's stuff are in order to be LGM, but you'd definitely need to in order to be level 30+ in projecteuler