Project Euler Forum

I wanted to report a problem I faced while giving answers to 2 of the problems.For 3 times it showed that the answer is incorrect.But some time later when I gave the same answer it showed that it is correct ,I faced the same in another problem as well!,please fix that error.

We will gladly fix any error, but before we are going to chase after it be sure that you:
1) don't type in answers manually; that is too error prone. Copy paste the answer your program is giving you.
2)Be sure that you copy paste correctly, that is
a) don't miss any characters from the front or the end
b) don't add any whitespace, the answer checker does not remove any additional whitespace.

Thanks a lot for telling that ,I usually copy paste the answer,but in case the answer is small I prefer manually typing that,though now I would copy paste even that.

The same error is creeping in each and every attempt to answer!!!!,It really confuses me whether my answer is really right or wrong.Please fix this error as soon as possible.

Allright, here goes.
I entered four solutions in a row: no problem at all.
Every week a new problem is published that is solved by dozens of people. No one ever complains about an error like this.
Every day hundreds of people solve one or more problems. I've never heard a complaint like this.
Of course there might be an error somewhere, but why is nobody else complaining then?
And what should we fix then?

I don't know why that is happening,but I am facing this problem for sure .Maybe it happens for specific problems,you may try for Problem 38 in which I faced the problem today itself many times.

I'm sorry but right in one go. So I really don't know what to fix.

Just a guess, but are you sure it is saying wrong answer, as opposed to the wrong captcha code? If you leave the problem page open while you are solving it then try to enter the answer a while later, the captcha would have timed out; you need to click on the captcha to reload it before submitting.

That annoyed me for a while before I got into the habit of clicking the captcha every time before submitting, so may be what piyush is experiencing.

If the captcha is not entered correctly, the site simply returns to the problem page without showing either a RED cross for a wrong answer nor a GREEN tick for a good answer.

I'm not too sure about the time-out range of the captcha but I tried it after a delay of some 10 minutes and it still accepted the correct answer. We need to know if piyush is actually getting a RED cross after entering his "correct" answer and what he eventually modified (if anything) to get his answer accepted.

piyush wrote:I wanted to report a problem I faced while giving answers to 2 of the problems.For 3 times it showed that the answer is incorrect.But some time later when I gave the same answer it showed that it is correct ,I faced the same in another problem as well!,please fix that error.

Not sure that this is relevant to the above, but I need to let off steam somewhere.

I have now spent about two weeks trying to see why my answer to problem 305 was incorrect. I've just entered the same solution yet again, as I couldn't see what was wrong; however I spotted a trailing blank remaining in the entry after copy/paste and removed it. The green tick duly appeared.

Most of your required solutions are numeric, perhaps with a minus sign or a decimal point (or comma?). Surely it's possible to do a minor bit of filtering of the submission and either
(a) warn the Eulerian that their entry contains illegal characters
(b) accept the answer if it's correct after removal of extraneous characters.

Alternatively, each problem statement could include a warning that non-numerical characters should not be entered.

"WYSIWYG" was all the craze in the early days of graphics screens. Now it seems that trailing blanks are numerically significant.

Mike

Hi Mike,

You make a good point. And I can certainly understand your frustration.

I've modified the scripts to "trim" white spaces.

[edit]I changed the script to display a warning message if any character other than digits, a decimal point, a comma, or a minus sign is found in the answer. However, it was pointed out that some problems require non-numeric characters and it is quite possible that future problems may utilise unusual symbols.[/edit]

euler wrote:digits, a decimal point, a comma, or a minus sign

Did you include the slash sign? The Luxury Hampers problem requires it.

Sorry, kevinsogo, I should have added to my edit... "So I've removed the 'unexpected character' checking part of the script."

I think you should keep the script, and only check for "invisible characters." Any other printable character is fine (the user will see that already).

It still trims the front and back of strings.