4 ms·

You are writing it differently with the goto. You can do the same with the for loop and it becomes symmetric again for (i = 0; i < n; ++i); for (i = n; i

by nedt 2y ago

You are writing it differently with the goto. You can do the same with the for loop and it becomes symmetric again for (i = 0; i < n; ++i); for (i = n; i >= 0; --i); (Note: not sure if intended that backward should run more often and include i = n)

trealira 2y ago
To be symmetric, the loops should read like this: for (i = 0; i < n; i++) for (i = n; --i >= 0; ) The second one could also be this: for (i = n - 1; i >= 0; i--) I say this because your backwards loop accesses the inclusive range [0, n] while your forwards range accesses [0, n - 1].
- torstenvl 2y ago
  for (i = 0; i <= n-1; i++) for (i = n-1; i >= 0; i--)
  - trealira 2y ago
    Yeah, that way of writing them definitely makes them look more symmetric. You could also do this, though it's a bit less pretty: for (i = -1; ++i != n; ) for (i = n; --i != -1; )
Maxatar 2y ago
Your post is a good example of how backwards iteration is so error prone and fragile. Your reverse iteration would result in an out of bounds access as well as unsigned integer overflow which results in an infinite loop.