[Edu-sig] Fwd: Which way did the chicken cross the road?

[Danny Yoo]

On Sun, 13 Oct 2002, Jason Cunliffe wrote:

> > He had been accustomed (over many uses of this problem) to seeing the
> > students end up with some processing upon elements in "increasing"
> > (left-to-right) positional order.
> >
> > He was surprised by a student from Israel, who developed an equally
> > valid solution which swept the array in *decreasing* (right-to-left)
> > positional order.

This reminds me of the electrifying shock I felt when I read through
snippets of code in TAOCP: in almost all of his inner loops, the index
variable decrements from n to 0, rather than from 0 to n.  The reason was
that a comparison against zero was slightly faster than a comparison
between arbitrary numbers!

(It doesn't take much to shock me.  *grin*)