The interview from Hades
I had an interview the other day. It didn't go very well (at least, I didn't
think so). Aside from a few questions (that I didn't think were well phrased,
and the hiring manager didn't seem to like my answers to) I was given a "puzzle"
to solve. I didn't solve it in the time alloted; apparently that killed my
chances as a candidate (it certanly ended the interview rather abruptly).
I find these new-fangled MicroSoft-inspired interview tactics to be very lame.
If anyone throws this one at you, you'll have had an opportunity to think about
it ahead of time:
The 17-minute Crossing Puzzle
4 people are "escaping from zombies" (or whatever). It is night. They have 1
lantern between them. They reach a gorge, spanned by a log bridge. There are
crocodiles in the gorge (or at any rate, it's very deep). They need to cross
the gorge before the zombies arrive (cross completely, then destroy the
bridge).
As with all such puzzles, there are various artificial constraints:
- The people have 18 minutes before the zombies arrive.
- They must cross the gorge in _less than_ 18 minutes.
- Only two people can be on the bridge at the same time or it will not
hold them.
- They need the lantern to cross; they can't cross in the dark.
- It's a long bridge and an old-fashioned lantern. You can barely see
your feet; you can't see very far ahead or behind on the bridge.
- It's OK to be left alone in the dark on one side or the other.
It gets more complicated (of course)
- Person A takes 1 minute to cross
- Person B takes 2 minutes to cross
- Person C takes 5 minutes to cross
- Person D takes 10 minutes to cross
(How they know this ahead of time is not provided by the puzzle gods).
Your job is to get everyone across the bridge, never more than two on the
bridge at a time, always a lantern on the bridge, in under 18 minutes so they
outwit the zombies
If you say "Oh that's easy" (AND get it right too :) you can go interview for
this job...
The answer is here