Recent News

Tag-Based Organisation (Tue, 06 Apr 2021)

It is with great pleasure today that a new tag-based organisation system goes live. Starting in May 2020, it has taken nearly one year of hard work behind the scenes and we hope that you find it a welcomed addition to Project Euler.

By default, tags are disabled for all members, but they can be enabled on your account page. You will find a drop-down box giving you three options: disabled, problem matching, and full tags. There you will also find a link: About Tags..., which explains in detail how the new system works.

Given the extent of the project, I would like to add special thanks to urimend who proposed the new system and has led the way from the beginning by guiding the whole development process. He has overseen and tagged the majority of problems along with wrongrook, which given the size of the problem set has been an incredible under-taking. And as always with new innovations at Project Euler, we owe our gratitude to hk, who has helped with tagging and offered his continued wisdom and insights during development.

Although there has been significant testing, with the best of intentions it is possible that there may be bugs or unexpected behaviour when a system goes live. So if you notice any issues, then please report them here:

(Tuesday 06 April 2021: Tag-Based Organisation)

Publication frequency and Summer break (Fri, 02 Apr 2021)

In order to maintain a high calibre of original problems, it is sometimes necessary to vary the publication frequency. After next weekend, problems will be published fortnightly until our summer break that will start the 11th of July.

Project Euler will be back after the summer break with a new problem on 2021-09-04 (Sat) 13:00 UTC.

(Friday 02 April 2021: Publication frequency and Summer break)

Site Maintenance (Fri, 29 Jan 2021)

Recently it has became apparent that Project Euler was suffering intermittent load issues. After closely monitoring performance during the busiest times it was determined that a complete overhaul of the way in which certain data is stored would be needed. This has required a significant change to most of the scripts and the way that data is stored in the database.

Today Project Euler was taken offline to upload those changes. It is hoped that this provides better stability during busy periods for many years into the future. But as always, with such extensive changes, it is possible that some unwanted critters may have slipped past the bugman. If you notice any unusual behaviour or bugs, please report it at the alternative forum:

(Friday 29 January 2021: Site Maintenance)

Site Update (Thu, 12 Nov 2020)

A new feature has been added that allows you to watch discussion threads. The link to toggle this is found at the top of each discussion thread page. When a thread is being watched, the problem ID will have a box around it in the problems table. But to help you keep track of these threads, you can now filter by Watched. Some members had said it was getting difficult to keep an eye on threads in which they had been following or were involved in a discussion among the ever growing problem set.

In addition, recently it was made possible to view problems in the Chronological order in which you solved them. This is another way to keep track of the most recent threads you might be interested in.

Finally, it should be apparent that the website has received some small cosmetic updates. Hopefully it helps to make Project Euler a little bit tidier.

As always, small changes can introduce unexpected consequences. If you notice any issues, then please report them at the following thread at our alternative forum:

(Thursday 12 November 2020: Site Update)

Wrong answer problem 728 (Sun, 04 Oct 2020)

The wrong answer for problem 728 has been corrected.
Apologies for the inconvenience.
Hopefully everything is OK now

(Sunday 04 October 2020: Wrong answer problem 728)