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Proposed Release Schedule for New Problems

  • Problem 681 is scheduled for Sunday, 29th September 2019, 07:00 am
  • Problem 682 is scheduled for Sunday, 6th October 2019, 10:00 am
  • Problem 683 is scheduled for Saturday, 12th October 2019, 01:00 pm

Recent News

25 August 2019: DB Migration Issue

To keep the website running optimally it becomes necessary for our hosts to periodically migrate the DB to a new server. We are very grateful for their diligence in this matter and it has always happened in the past without incident. However, today it seems that some of the data on the new server became corrupt during the transfer. Consequently it was impossible to sign-in, giving the impression that your account no longer existed. Fortunately, all the data remained intact on the old server.

So once the issue had been reported our hosts were able to point the site back to the DB on the old server before carefully ensuring that all of the data was migrated properly this time.

We are very sorry for the inconvenience and the scare this might have caused some members when they thought for a moment that their accounts had disappeared.

The site is now pointing at the DB on the new server and it should all be working as expected. It is highly unlikely that any data has been lost during the migration, but if you solved any problems in the last day, then for your own peace of mind it is recommended that you check no progress has been lost.

20 August 2019: Pinning Problems

A change was made recently to the website that allows you to pin problems. This should be useful if you wish to return to a particular problem.

At the top of each problem page you will find a small icon in the top right corner allowing you toggle between pin/unpin. Once a problem is pinned the ID will appear in blue on the problems table page and it will be shaded blue on your Progress page. In addition, on the Archives page you can also filter problems by pinned. Please note that currently each member is limited to ten pins.

Hopefully this proves to be a useful addition to Project Euler. If you spot any issues, then please use the thread:

17 June 2019: Summer Break

Problem 677 on Saturday 29th June will be the last problem of this season. Project Euler will then take a summer break, returning with a new problem on Saturday 7th September.

3 March 2019: Style Sheet Update

As technology has evolved it seems that Project Euler has taken time to catch-up. A common request in recent years has been to modify the style sheets to be make the website mobile device friendly. This includes a responsive framework that should dynamically adapt the display to accommodate a variety of screen widths.

It has taken a lot of work, given the regimented tabular structure of many pages, but we are pleased to reveal the fruits of that labour.

This has required significant changes not only to the style sheets, but the way in which the scripts dynamically produce pages. Extensive testing has been made, but as you can imagine there are going to be some setups that had not been anticipated and consequently pages may not render as expected. In addition, as part of the the process a number of decisions have been made to modernise the style sheets, including the use of CSS variables to simplify future changes. Whereas support for this has been in place in all of the main browsers for several years now, it does mean that some old browsers may suffer. Special provision has been made to provide legacy CSS support for Internet Explorer, which means that IE will only render a version of the default theme .

If you notice any specific issues, then we would ask you to report them at the following address on our alternative forum.

For many members they will notice nothing more than, what we hope, a cleaner more pleasing appearance. For mobile device users we hope that the effort was worth it and navigating the site becomes an enjoyable experience.

20 October 2018: Weekly Publication Schedule

About a year ago we decided to reduce the release of new problems to one problem every two weeks.

Thanks to the many contributions made by our members we now have enough problems in stock to release one problem every week. Because we don't want the authors to wait too long before their problem is published we make the following decision: At the start of each new batch of problems (usually 6 problems) we will make a decision to release those problems weekly if there are sufficient problems in stock; otherwise we will follow a two-weekly schedule for that batch of problems. At the top of news page you can always see when new problems are released.

We hope that members will keep contributing enough proposals to maintain a weekly publication scheme.