I have completely the same solution!

You actually managed to make shorter version...

You have a list of 2 numbers: [0, abs(res)].
If the (res<0) returns True then the second item is taken. That is because True is the same as 1 in Python and the item with index 1 is abs(res).
If the (res<0) return False then the first item is taken (False = 0 in Python). So the item with index 0 is 0 in that case

This is O(log(n)) solution using binary search

omg, I also thought about dp but came up with simpler solution.
Nice one btw

This kata can be solved without applying special formulas from Numberphile video. It is just for educational purposes. Try to come up with something "easier"

Thank you!

Changed the name of the function to camelCase

Wow, so clever idea, but it runs out of time when const bound = 1e9 + 1 :(

I think I should make tests more separate. For example, divide them into Random tests with large A values (A <= 10^9) and Random tests with small A values (A <= 10^6). Also, add more false cases to the Example tests.

Thank you for this information

Thank you, hobovsky, for your long comment!
I made the changes for all languages and now Incorrect answer for a=x is printed whenever test is failed. It took me a while to implement this feature for C++ but it was worth it.

Cool, you used the optimised strategy :)

Yes, providing three languages at once is boring :/

I am confused. So I should provide the information likeA = 3 (printing the inputs when test is failed)???