Thanks a lot! Happy sunday :)

No idea, I verified your solution and it's marked as valid now.

Why is this solution marked as 'Invalid Solutions: These solutions originally passed when...'? I just completed this kata without any errors whatsoever. It's highly unlikely the test cases have been updated just a microsecond after I submitted my solution.

What's the error here?

In pyton 3, yes. In python 2, / does the floor divison if you use integer for each operand.

I have stucked here too :(
So it is also possible to get the number to be integer using integral division "//".

Welcome to Codewars!

You can print the input parameter directly to the console so that you can see where you went wrong.

I am new to the community. I was working on a challenges and my code passed 9 out of test cases. I really want to know which case did the program failed so I could figure out why the code was not running properly. Is there a way I may know which test case I was wrong?
Thank you for your time

Um, it would also be nice if I can see when I (and maybe other users too) completed a kata in a language.

It would be in my profile, something like:

Completed in languages: Ruby on November 22nd; Python on November 23rd, etc.

Doesn't work with really large m or n anymore. I failed at n = 45001 and n = 450010. The tests now go far beyond that.

Thank you for your answer. Such application of maths into CS.
I ended up looking through Bernoulli polynomials, Nicomachus's theorem, Faulhaber's formula and stuff, none of which I understand.

But I'll start reading more on Maths from now. And on algorithms.
If you can kindly point to some resources, that'd be so great.

But thanks again for your inspiring solution.

Yep. My solution is accepted, and it's wrong.

There is a small error in the Ruby version.
Instead of
//TODO: complete ,
it should be
#TODO: complete

Fixed. Thanks.