Project Euler Forum

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.

On the About... Tags page, first line in the answer to the second question, there is a typo: "sovler".

The selection of unsolved problems or other subsets does not seem to work when looking for a specific tag.
See http://81.88.24.251/eulerbug/Euler-Tags-Problem.jpg for an example. I had selected unsolved, but the list shows me all problem for the given tag.

When you are searching tags, all other filters and the ability to sort are temporarily disabled.

I noticed that Problem 707 has one visible tag (and a few hidden ones), and when matched to Problem 559, it says "2 tags matched".

I suppose there is a tag that is hidden to 707, but visible to 559. Is this correct?

Good observation! You're right that there is currently an unavoidable anomaly. I've passed it on to the team and we shall discuss it.

I had enabled Full Tags, and it'd been working for several days. However, the tags disappeared in problem pages today. What's more, when I typed in some frequently used tags like combinatorics or polynomial and clicked search, I didn't get results, but
received a message reading "Removed 1 unrecognised tag from your search."
I have confirmed the tags were still enabled, and changing the settings didn't make tags appear in the problem page.
Please take a look at this issue, thanks.

I have the same problem as castrate.

I also experienced the same problem temporarily. I have no idea what caused it, but could you check to see if it is working again?

It works again today. Thank you euler!

Working for me again as well. Thanks!

Tags should be mentioned on the main About page next to hints. The only reason I found out about them is by chance looking through my account settings.

Good idea. I've added the following short paragraph to the section "I just can't figure out how to solve a particular problem. What should I do?"

Another option is to enable tags from your Account page. You will be able to find a link next to the option on that page that tells you more about tags and how they can provide hints when solving problems.

euler wrote: Tue Feb 13, 2024 4:51 pm Good idea. I've added the following short paragraph to the section "I just can't figure out how to solve a particular problem. What should I do?"

Another option is to enable tags from your Account page. You will be able to find a link next to the option on that page that tells you more about tags and how they can provide hints when solving problems.

It should also refer to the about-tags page
https://projecteuler.net/about=tags

On the About tags page, https://projecteuler.net/about=tags, there is a typo under the description of FullTags+

"incldued"

Thanks. Fixed.