how i make random tests?

also how i add you into contribution

uploaded the code soon as possible

thank you for your code, helping and solution,
may i ask you how i make random test (if you know) i will be forever grateful for your action

there few problems:
1 lack of documentation
2 seems like there some errors on random testing
3 its not damn 7 kyu, is probally idk 3-5 kyu, thoguht might be skill issue