i like it! my way but shoter)

There are tests with x == 0 or r > x.

• No random tests.
• Tests should not print.

how does the last one works (s6)? i can clearly see it working on a simpler example, but i don't get why it returns the corresponding integer

In your example, the lowest possible value shouldn't be 10 ?

It seems to me that if z is always the lowest possible value, z must be equal to r ?

Turning @jungerstein's comment into an issue:

Please add to the description that either z > x or z >= x.

Although in the description, the 'lowest possible value' for z s.t. z % 13 == 10 is 25 (so that the answer will be 7), it is not the case.

The lowest possible value do not exist if you just restrict z, x, y being integers. The integer z could be negative, and as small as possible [if the definition of the remainder r being a = bq + r where 0 <= r < abs(q) is applied; I know sometimes the operator % behaves differently when negative integers are involved] -- so do not forget to add positive in the kata description.

Even z is restricted to be positive, its 'lowest value' is still not 25 in the example. It has to be 10, because 10 % 13 == 10 and any number in 1..9 does not rest 10 if divided by 13. So please do not forget to restrict again z > x.

Same here!!