ISBN check digit puzzle


Perfect, thanks! That helped a lot to find the error in my code (uninitialized integer => 0, interpreted as correct checksum sigh)

No, i was just referring to the string indizes, so my count starts with 0 instead of 1.


so my count starts with 0 instead of 1
I see. Then try out the new samples, and look out for invalid format besides only checking the last char.


I completely rewrote my code. Now I pass all test cases but fail on the third validator. I think I just pass on this puzzle. It caused way too much anger.


msg me your code perhaps I could show you what's wrong


fyi i got it working with your recent changes to validators. :+1:


:+1::+1: :computer:~~



I have passed all the tests, but I cannot validate the example validation.
Do you have any hint about the test which could cause it ?

Thank you.


Hi, i have an issue I don’t understand with this game, in the last validator, I found that this is an error and the validator says it’s not :
but the sum == 112
112 % 10 = 2
10 - 2 = 8
6 != 8 so there is a mistake, I don’t understand why it does not pass


Hey @m1602,
9780134177296 is not in the validation tests set, it is in the last test case. And it is rendered invalid.
I’m confused a bit about what your issue is. Do you mean that the last validation test fails (upon submission)?


Hi, thanks for the answer, I got this ISBN in “Much longer” test, I’m trying to validate all the editor test case before submitting
I’m writing it as invalid but the test seems to say it’s not

Actually my mistake seems to be somewhere else, I think I found it, I must have misread something in the result cause I can’t reproduce my previous problem, sorry