I'm not proud of this :(

Very smart solution But I'm not sure it's a good practice. I mean, without context of requirements, with the naked eye or the first impression, it is not clear what the code is doing. What do you think?

O, thanks a lot! I was looking for a bug in the wrong place:)

Float parameter "bounce" must be greater than 0 and less than 1

You have an infinite loop in your code when bounce is 1.

You are right, my mistake. I returned ArgumentException. Sorry for the incoveniences.

If all three conditions above are fulfilled, return a positive integer, otherwise return -1.

You need to validate the input values.

requeriment: Float parameter "window" must be less than h.

But test examples is less or equal to h... so the window can have the same height to the building...