Is there a code that is more optimize than this?

Question

I did the code in C Language about n Choose r
and it takes a long time when doing with 8C4.
And what is the Big-O Notation of this code?
Thank you in advance.
https://code.sololearn.com/cIT8JkyOdZ3i/?ref=app

Answer 1

You have a tiny bug: line 17 should be
"for(int i=num; i<=n; i++){".

Other than that, your code seems quite fine to me! It finds and prints each combination exactly once. So I think the time complexity should be O((nCr) * r), which is obviously the best one can expect.

What made you think it takes a long time?

Answer 2

I must have written that in a state of sleepy deliriousness. I guess running the code would have helped. I'll... just quietly delete that :D

Answer 3

Schindlabua I knew that but I'm afraid that it would take more time using nCr recursive.