Code coach challenge

Question

1 test case failed. Any explanation as to why?
https://code.sololearn.com/cRAVLjwNl0KK/?ref=app
https://www.sololearn.com/coach/51?ref=app

Answer 1

just add

rstr[len]='\0';

before printf("%s",rstr);

it marks the end of the string.

Answer 2

John Robotane thanks

Answer 3

can you post the code coach description?

Answer 4

John Robotane Extra Terrestrial