Could I again get some help in improving this code?

Question

The 1st link shows how the code looked before. And I would like to thank Coder Kitten , Volodymyr Chelnokov and Nayeem Islam Shanto...শান্ত for helping me reach so far with this code.
But now i have another problem, check out inside the 2nd link. Could I get some help guys? Once again?

https://www.sololearn.com/discuss/2591536/?ref=app
https://code.sololearn.com/c3R1T5hB5lqy/?ref=app

Answer 1

The size of the code is not relevant in regards to the execution time.
I made a simpler program which requires less calculations, but this solution I am giving is probably not the one you were supposed to find to solve your homework.
Note that the program works even with characters 😅 you can make some modification to allow only numbers.

https://code.sololearn.com/cCVLzc0T6Vk2/?ref=app

Answer 2

The problem with getting the time limit is not that the code is too big, but that you have a while (i == 1000000) inner loop that never modifies i, so once you get inside you can never leave.

Still the code being too large is a problem (first of all, because it hinders understanding the code)

What i'd do:
a) have a boolean flag saying if we have printed anything yet (initialized with false)
b) inside the loop if flag is false,
if a is nonzero, print it (with no extra zeroes) and set flag to true.
If the flag is true, just
printf(",%03d",a) -- %03d specifier says that the field must be 3 digits wide, with unused digits printed as zeroes - just what we need.

Using flag variables is ugly, but here i don't know how to do better - maybe someone else advices a better way.