I wrote Problem 371, https://projecteuler.net/problem=371 , as a high school student in 2012!

I'm so happy to have spent twenty years of my life learning math and solving problems on Project Euler and elsewhere.

I wrote Problem 619 (https://projecteuler.net/problem=619) which was published on 2018-01-27 and solved by 474.

The problem was based on 2013 Putnam Exam problem A2 (https://kskedlaya.org/putnam-archive/2013.pdf) which I took at the end of undergrad.

I got an email six years later (in November 2024) telling me they accepted the problem:

Greetings!

Please excuse the email. It's quite possible that you are no longer active at Project Euler, but we are currently trying to retrospectively acknowledge contributors of problems.

You were identified as being involved with Square subsets [619 m] in Sep-17.

If you would like to be added as a verified contributor, please reply to this email and provide the username you currently use at projecteuler.net. Please note that contributor usernames will not appear publicly, rather they will be used internally to unlock new contributor awards we are introducing.

Regards,

Project Euler Team

Ha! I did a lot of these around 2007-2008. I solved the first 100 or so ones. Solving these were more fun than any other programming problems site I've seen. I quit it when I realized I was spending 4+ hours per problem - I couldn't justify the time.

Beyond a certain point, most required some knowledge of elementary number theory.

This website was a part of my education as a computer scientist and seeing it here again I'm curious for the full story of how this site was made. Who made it, what do they do now, is it part of a broader project they have?

There is only very basic info here: https://en.wikipedia.org/wiki/Project_Euler

The most fun on this site is solving a problem and then having your mind blown by solutions in Apl/j/k and trying to guess what they mean without knowing anything about those languages

Since this is still on HN frontpage. Does anyone suggest any math books to help solve these problems. I am pretty sure you can't solve problems above 50 without strong maths background.

These are both a lot more fun, and a lot more educational than leetcode problems. Strongly recommend for anyone looking for practice problems when learning a new language or whatever.

I have done Project Euler very sporadically since high school. To date I've only done problems 1-54. Despite this, I think the website was a big contributor to my love of programming. I found it before knowing about leetcode and I think it prepared me well. I think I owe Project Euler a decent %-age of my eventual entry into Software Engineering as a field.

What's really neat is that most of the problems are so compact that you can just read about the full problem, then spend hours and days thinking about possible solutions.

I created a PDF version that I keep on my Remarkable for puzzling: https://github.com/pveierland/project_euler_offline

Project Euler spurred my love for math and programming when I was 15. I got through the first few with pencil and paper and then quickly realized I was going to need to learn how to program. Got started with Java (in Eclipse) and then moved on to Python. I feel like it completely changed the trajectory of my life.

No one tells you that they delete inactive accounts. I used to have over 300 solved problems htere. Now it is all gone, all the effort, but the skill remained of course.

I ranked on that once! I was like the 23rd person to do one of the new problems one time. Just about as low as you can rank. It was a fun puzzle but you had to be awake at a funky time to do it.

Thousand of hours on this. Love it.

One of my best memories was in undergrad there was one semester in 2013 where half a dozen of my CS classmates and I competed to try and solve the most Project Euler problems. We had a leaderboard and everything.

I saw first hand how much faster my friend’s Java solutions were than my Python solutions.

Good times.

Are there other similar sites? I remember this one, for bioinformatics

https://rosalind.info/problems/list-view/

There is a somewhat similar idea behind "Ponder This" by IBM https://research.ibm.com/haifa/ponderthis/index.shtml They post a problem every month and in the end post a solution. I used to spend a bit too much time on those.

I solved a few using AWK, fun: https://github.com/ketancmaheshwari/projecteuler

I attribute project euler for instilling the playful enjoyment of writing programs in college while I was studying electrical and computer engineering. I owe my career to it!

Like many others here, Project Euler was foundational in my education and growth as a programmer.

Leonhard Euler himself is an incredible figure and arguably the most prodigious contributor to mathematics throughout history. So much so that people started naming things discovered by him after the next person to have proved them.

https://en.wikipedia.org/wiki/List_of_topics_named_after_Leo...

Project Euler was what I used to get comfortable with my two main languages -- first python and then rust.

I loved to solve it and then look through all the different solutions and find pretty ideas and idioms.

I learned so much from this site- including that so much education comes from being prompted to ask the right questions.

After opened https://projecteuler.net/ I got

403 Forbidden Request forbidden by administrative rules.

Note: I didn't know and open this website until now.

I love a good puzzle solving club. Some of my favorites: https://www.themastertheorem.com/ https://en.wikipedia.org/wiki/Perplex_City https://en.wikipedia.org/wiki/MindTrap

A great one of my favorite websites of the past. Wonder how they are coping with the issue of their users using AI to solve problems.

I think a hat-tip is due to freeCodeCamp for introducing Project Euler (along with Rosetta Code) to a new generation of programmers:

https://www.freecodecamp.org/learn/project-euler/#project-eu...

I discovered project euler as a novice programmer in high school around 15 years ago. I loved how solving a problem unlocks a secret forum only available to other solvers. I would spend hours reading through everyone's prior solutions and trying to understand them. One guy had tagged his profile as "haskell" but would always provide his solutions in ruby which threw child-me for quite a loop (I actually thought ruby and haskell were the same language for some time)!

Wow, I can't believe this is still around! I'm glad to see artifacts from the past like this are still out there on the internet.

Makes me miss Google CodeJam though.

I remember it vaguely but there used to be a badge awarded for being among the first 100 people to solve the problem. I was obsessed with getting that badge to the point that I spent obscene amount of time solving the-then recently released problem even when the following day was my final exams. I did manage to get that badge though. This was circa 2013. Fun times!

So, to remind myself, Euler's name is pronounced more like Oiler, right?

I love running euler problems when trying to learn the basics of a new programming language. I have a small collection of programs in like 10 different languages that I keep around as a reference for things because I always try to use language-specific features to solve the problems, and then I reference them as examples.

So much more fun than leetcode. OTOH, unlikely to help you in an interview.

I too owe had my love for programming captured through project Euler. I am immensely grateful to my maths prof who introduced me to it.

I also love looking back at my old PE code and having absolutely no idea what it doing. No comments, no docs, no notes. From a different era.

I remember visiting Project Euler back in 2013/14 or so. Was really my first introduction to programming exercises as youngin. Probably did fifteen or so of them before ADHD kicked in though. A small gem on the web.

I did a lot of these when I was around 15-16 and it solidified for me my interest in CS but in general abstract thinking and problem solving. Great site.

i was a euler fanatic some years ago reaching problems in the 500s albeit, skipping problems along the way. at that point, too many problems required a deeper math background than i possessed so i abandoned it. what amazed me was that others composed solutions that solved problems in mere milliseconds that brute force approaches would still be running when the universe cooled to absolute zero.

Anyone else having problems registering? or is my solution to Problem Zero wrong...

Anyone else having problems registering or is my solution wrong?

The leetcode before leetcode. Hail.

very surprised this project is still releasing problems weekly - I remember this being up when I was in high school. maybe I'll pick it up again since I only did the first ~30 or so back then.

How I learnt about prime number sieves.

Good prep for Advent of Code in 2 weeks.

this is how you end up getting into APL/array langs for sure.

Thanks for reminding me this; I'd try to solve them both in Scheme (s9fes) and JimTCL.

2007 I remember writing one-liner ruby solutions up to 100.

Hackerrank also used to host(still has?) PE problems with additional test cases.

Glanced at the exercises. It appears that two of them have numbers arranged in a triangle and ask for a longest path.

Hmm. Given such a triangle, let m be the largest number in the triangle. For each x in the triangle, replace it with m - x. For the resulting triangle, solve it to give the shortest path using one of the well known network shortest path algorithms.

fake frustration yet another thing named after euler.