Project Euler Forum

Can a char be repeated in the passkey?
i.e. 51515151?!? (it is just an example)

The problem text doesn't disallow it.

Thank you anyway ( ), solved

Hi, this is my first post, I've been enjoying the website a lot.

My issue is very little, really. Problem 79 reads "they may asked for the 2nd, 3rd, and 5th characters"
Isn't the word "be" missing there? "they may be asked"

That's it. Thank you, everybody.

Good spot; changed it to "they may ask for the 2nd, 3rd ..." (meaning that the security system(s) may ask...)

Before starting a new topic, please make sure that the topic of a particular problem does not already exist (otehrwise this forum becomes extremely mess...)

Hi everybody,

I'm a little bit confused with this problem. I have to find the smalles count of digits number, for which are numbers in keylog.txt possible solutions. And numbers in keylog.txt have form XYZ where, Y is between X and Z in for me unknown number?

jozefovovic wrote:I'm a little bit confused with this problem. I have to find the smalles count of digits number, for which are numbers in keylog.txt possible solutions. And numbers in keylog.txt have form XYZ where, Y is between X and Z in for me unknown number?

Yes, that's it. The answer contains X,Y,Z in that order, usually with other numbers in between.

Hi, this my first post on this forum !
I want to thanks all who have created this website just awesome !
i have a little missunderstood for this porblem , because english is not my mother tongue !
What do we mean by the "the shortest possible secret " do we mean the length of the passcode???
The file KeyLogs containt always the 2nd, 3rd, and 5th characters??
[If any one can explain what am i supposed to do it will be excellent]
I'm sorry for my questions may be stupid ! but i'm really confused !
Thanks so much !

satyres wrote:Hi, this my first post on this forum !
I want to thanks all who have created this website just awesome !
i have a little missunderstood for this porblem , because english is not my mother tongue !
What do we mean by the "the shortest possible secret " do we mean the length of the passcode???
The file KeyLogs containt always the 2nd, 3rd, and 5th characters??
[If any one can explain what am i supposed to do it will be excellent]
I'm sorry for my questions may be stupid ! but i'm really confused !
Thanks so much !

"2nd, 3rd, and 5th characters" = this was just an example.

For example, if the passcode were 846295784, and I asked you for three random numbers, I might ask "What is the first, third, and sixth number?" You would answer with the login "865."

keylog.txt contains many successful logins for the same passcode (three random numbers from the passcode, in order). So if you have some valid login xyz, then x comes before y which comes before z in the passcode. The question is asking for the shortest possible passcode that satisfies all the login attempts in keylog.txt.

Let me know if you have any more questions!

Marcus Stuhr wrote:

satyres wrote:Hi, this my first post on this forum !
I want to thanks all who have created this website just awesome !
i have a little missunderstood for this porblem , because english is not my mother tongue !
What do we mean by the "the shortest possible secret " do we mean the length of the passcode???
The file KeyLogs containt always the 2nd, 3rd, and 5th characters??
[If any one can explain what am i supposed to do it will be excellent]
I'm sorry for my questions may be stupid ! but i'm really confused !
Thanks so much !

"2nd, 3rd, and 5th characters" = this was just an example.

For example, if the passcode were 846295784, and I asked you for three random numbers, I might ask "What is the first, third, and sixth number?" You would answer with the login "865."

keylog.txt contains many successful logins for the same passcode (three random numbers from the passcode, in order). So if you have some valid login xyz, then x comes before y which comes before z in the passcode. The question is asking for the shortest possible passcode that satisfies all the login attempts in keylog.txt.

Let me know if you have any more questions!

Thanks so much for you help ! i solved the problem !

There is nothing in problem 79 that states you MUST have digits either between the passcode digits, not before, nor after. the example is just an example. "the three characters are always asked for in order," there are a max of n digits in the data file provided, so the answer is simply n, the length of the longest valid password.
If the problem statement "The bank WILL prompt you with an arbitrary string of digits that include the digits of your passcode" then the problem statement is clear. As it stands now you might ASSUME that will happen, but you should not be making any assumptions. Problem 79 (View Problem)