Can you please explain why it works?

I just changed the comment on Python that read "#your code here; you can use % but your are lame if you do ;)". I think we should not be shaming beginners if they don't know how to do this or that.

I don't get it.
If you're saying "no more than X people behind" that includes a scenario at the extreme where there are 0 people behind.
Similarly, when you say "No less than Y people ahead" that means that in the best possible scenario (for Vasya) there are exactly Y people ahead of him and no more.
Hence, the maximum number of options for Vasya should simply be p-Y.
However, this doesn't work. For example:
Test: Testing 9 people in line, at least 4 ahead, no more than 3 behind:
Answer: No more than 3 people after Vasya: 5 should equal 4

Help?
Thanks

Why doesn't x = str(1/0) simply work?

As a general note, I dislike katas with "Simple" in the title. It may be simple for some, but others may struggle and the title puts added pressure on them.

how does it work? if the number is 18 for example, 18%9==0, while sum of digs should be 9.
thanks!

Can someone please explain why this works? Thanks

Great solution.
Could you please explain what the complexity of this solution, and compare it to the complexity of iterating over the list?

Could someone please explain? Thanks!

What's the O(n^2) solution ?

I may have it wrong, but I'm not sure this handles cases where the sum of the entire array is 0. When I ran this code for arrays like [-10,10] I get -1, where per the instructions the code should return 0.

In python, I'm seeing things I don't necessarily understand. LIke:
[25, 25, 25, 100]
Shoud equal NO.
But, in this case, I have $75 in the till when the person with the $100 comes, so I will have $75 to give back as change.
Help please?