Project Euler Forum

New awards have been added along with a number of visual tweaks to sections of the Progress pages to support them. Some of them should be obvious, but others might appear a little mysterious.

• Three Strikes!: Get the diagonals in any three grids
• Perfect Game: Get the diagonals in all possible grids
• Unknown Conqueror: Five times lucky, five times smart
• Tag Explorer: Solve at least one problem for one-hundred different tags
• Mount Euler: Mastering the mountain of difficulty
• Centenarian: Solved a problem on one-hundred different days

Two existing awards have changed slightly: CC for Continued Commitment has changed from solving the first two-hundred problems to complete any two grids and similarly, D for Dedication has changed from solving the first five-hundred problems to complete any five grids.

We hope you enjoy the changes.

Wow, I have to be the first person ever (modulo site update time) to have CC for Continued Commitment, but not C for Commitment

For the Centenarian problem, what's the definition of a day? Is it a 24-hour period between two problems, or Monday/Tuesday... (which would depend on the time zone?)

Swistakk wrote: Thu Feb 06, 2025 8:26 pm Wow, I have to be the first person ever (modulo site update time) to have CC for Continued Commitment, but not C for Commitment

That made me chuckle too! For the sake of consistency, I've changed C for Commitment to complete any grid. So not only were you the first, you might have been the only one.

thedoctar wrote: Fri Feb 07, 2025 1:19 pm For the Centenarian problem, what's the definition of a day? Is it a 24-hour period between two problems, or Monday/Tuesday... (which would depend on the time zone?)

It counts the number of unique days, between 00:00 and 23:59 on a particular date in your own time zone, on which you solved a problem.

Not sure if this is related to this update, but I have not received a CC for Continued Commitment reward today that I should. (I have solved the first two grids)

Three Strikes! and Perfect Game also shows that I have 1/3 and 1/9 progress instead of 2/3 and 2/9

Thanks for reporting. I'll fix it when I get a chance.

Okay, so I have received the CC reward, but only after solving 201th problem (In different grid).

Yes, it was caused due to bad programming logic.

As the script scanned through your problems in order, it was keeping track of the number of problems solved in a grid (and the number of diagonals). When it found itself in a new grid, it checked the running totals, and incremented the grid complete or diagonals complete counters respectively, then reset the problem solve counters. However, as you had solved every problem in two grids, it never got to the third grid to do that check.

It should be working as intended for everyone now

On my progress Awards page I see "89/100" on Tag Explorer award but on my progress Tags page I see "103/145".
Is this a bug?

There doesn't seem to be an account "FourLegsDriveCat" on the main site. Let me know your .net username and I'll change it here at .chat to match, then I'll look into it.

euler wrote: Sat Aug 16, 2025 12:39 am There doesn't seem to be an account "FourLegsDriveCat" on the main site.

Ah, yeah. I forgot that I changed my user name there to "Valentyn_Shtronda".

Actually, it is very confusing and it's to do with hidden tags. The awards page count is correct (89 currently), but that is based on your preference for tags. You have chosen Full Tags which shows the names of the tags, but will not reveal problems that have those tags hidden. For example, there are 18 problems that use the tag: bisection, but 14 are hidden. You have solved 3 of those problems with hidden tags. So when it counts the number of problems for which you have solved at least one tag it will not include bisection.

There was a bug, in that the tag explorer section of your Progress page was counting those hidden tags; I've fixed that now.

Where it gets confusing is that if you change your tag preference to Full Tags+, which shows hidden tags, your count will increase to 103 based on your current solve profile. This means you could earn/"unearn" that particular award if you are on the boundary (like you) and you switch your tag preferences.

The team discussed this issue at the time and we couldn't find a perfectly satisfactory solution at the time. However, having now fixed the count on the tag explorer section so that both sections have the same total, it shouldn't create the same confusion it clearly caused this time.

By the way, would you like me to change your username here to Valentyn_Shtronda?

Thank you for the explanation and the bugfix.

Let me express my ideas and sorry if your team already discussed this.
To avoid earning/unearning the award when account settings are changed, I would exclude hidden tags from Tag Explorer award counter, even if the setting is Full Tags+. So there will be no ambiguity and everyone would be in equal conditions.
To avoid any confusion on Tag Explorer page if the setting is Full Tags+, the counter could be broken down. For example:
"Solved at least one problem for 103 of the 145 tags (61%).
(89 visible and 14 hidden out of 125 visible and 20 hidden)"
If the setting is Full Tags, there is no need to break it down.

euler wrote: Sat Aug 16, 2025 1:07 pm By the way, would you like me to change your username here to Valentyn_Shtronda?

Yes, please.

That was a good idea to lock the award into visible tags. Along with that I've made some additional changes which, I hope, makes it clearer to everyone now. The tag explorer section of the Progress page now shows bars for visible and hidden tags. Searching will not reveal the problems using those hidden tags if you haven't chosen Full Tags+. The main reason for this change is that the view remains the same for all tag enabled options. Switching tag options and seeing your totals change is not only confusing, but could be frustrating if you thought you'd maxed out a particular tag.