GUIDELINES:

Look at main(): it calls various functions.
You are asked to implement two functions: str_cpy() and str_cat(). No need to implement str_printf() and str_free() (Jungo employees: you are required to implement them).
Reading main() carefully will allow to understand str_cpy() and str_cat() signature and usage.
The code you write needs to be "library quality"; as good as you would expect a good libc to implement such functions.
At the top of the page, you see 4 includes - indicating the functions that can be used to implement str_cpy() and str_cat().
FYI: It is possible to implement str_cpy() and str_cat() efficiently in no more than 7 lines of code per function, and in less than 5 minutes.

/********* comments from the company after submittin my solution ****************/

Hi Hod, Before I can give you a detailed feedback for your solution, there are some major bugs in your code which may have been caused by a hasty submission.

I suggest you re-read your solution very carefully, fix it up, and resubmit.

In addition, please note, we are looking for generic implementations of str_cpy and str_cat, which will work well in any reasonable use-case.