Project Euler Forum

Problem 225 (View Problem)

This is a minor nit, but we are looking for the 124th smallest, positive, odd integer that doesn't divide any terms of the sequence, yes?

Any chance this can be made public?

I'd read your blog if it wasn't for the inadvertent spoilers sprinkled in. Nothing specific, but I don't want any hints or ideas for how to solve problems. For anyone like-minded, beware.

kenbrooker wrote: ↑

Sun May 24, 2020 1:19 am

AND/OR change "his" to "its"?

Agreed.

Any chance the light green color that highlights the entries that are used in the example sum can be changed to a different color that is not so annoying to look at? Maybe something like red?

Do I understand the problem correctly? That is hard to tell from your own description. Let's restart using your own data and hk's suggestion. - First let's "encrypt" your HELLO WORLD with your encryption key 'abc'. Rotating the key for XORing each character of the message, the end result would be a...

I finally solved this one. I beseech the moderators to completely overhaul the wording of this problem, because as it is written it might as well be a 50% difficulty problem rather than the 5% at which it is currently listed. Pretty much all the difficulty of this problem lies in figuring out what t...

kenbrooker wrote: ↑

Fri May 22, 2020 6:59 pm

By Animus, this is a key to answering your question --

There is no separate decryption key, it is the same as the encryption key

Can you tell me if my understanding is correct, as reflected in my previous post? A simple yes or no will suffice.

As I understand it, each letter was given a number, and that same number is used each time the same letter appears. No, that would have been encryption via substitution and has nothing to do with the described XOR encryption. Now what exactly is a decryption key? If it is supposed to give you the v...

Typo in the first sentence of the problem statement. The word 'of' doesn't belong there.

I think it would be useful for users to be able to sort a problem thread by kudos.

Is there something... Evil about cleverness that I am not aware of? That needs to be "prevent"ed?! Surely you jest? Nothing wrong with cleverness, but I do think that one of the qualifications for a problem to make it to PE is that it should be a true combination of math and programming, so a probl...

Some "rules" for Roman Numerals even state -- A numeral can be repeated in succession up to three times only. Allowing only four repetitions at least avoids the conflation "VIIIII" = Ten vs "X" = Ten... Just some random thoughts... True. Although allowing more than 4 would prevent clever people fro...

Why is this note

"Note: You can assume that all the Roman numerals in the file contain no more than four consecutive identical units."

included in the problem statement? Why can't we have more than four consecutive identical units?

Are we only considering sums that have at least two summands, as in problem 76? Please update the problem statement if yes. Thanks.

If I go to Progress/Posts when signed in to PE, it says

Posts made x (y)/Kudos earned z (w)

What does this mean?

s4mp wrote: ↑

Wed May 06, 2020 10:00 am

I've looked through the thread and that answers about the ace but i still cant work out why im off by one.

Is there any chance i could PM you a list of my results for each pair of hands and you let me know which one is wrong?

Sure. But how do you know you're one off if you haven't solved it yet?

I'm still having trouble understanding the problem. What does it mean "the key is repeated cyclically throughout the message" and "as the encryption key consists of three lower case characters"? As I understand it, each letter was given a number, and that same number is used each time the same lette...

There is a thread about this problem already. Did you look there?

viewtopic.php?f=50&t=6550

By the way, how do you know you're one off if you haven't solved it yet?

Actually Lilstalker didn't ask you a question. Lilstalker translated the question of the problem to the translation if it he gave you. That you are not able to understand that he didn't ask you a question is not my failure. What is the minimal number of tries that will guarantee that the device is ...