very smart

i did the same thing but with for loop,and even tho for loop has less time complexity,it still got timed out,and i dropped this approach

Is it best practice to change the value of a variable in the while loop condition?

This one shows very good and creative thinking.

Of course, but you need to remeber that this task is designed for starters.

" " is not the only whitespace

In productive code, I prefer i - n instead of using i + (n * -1) to avoid unnecessary computations. That was a long time ago but I think, I wanted to show how I came up to this solution.

oh sorry, I was thinking i - n and I have 1 unintentionally written i - 1

Maybe it's not the same formula:

i + (n * -1) = i - n

You need n in your formula, otherwise you don't know how far you should rotate.

i - 1 won't work for n > 1 in my solution.

instead of the if statement you could've used c += i % 2 directly

why not use i - 1 instead of i + (n * -1) ?