Program logic bugs vs input/environmental errors

[eles via Digitalmars-d]

On Wednesday, 8 October 2014 at 07:00:38 UTC, Dominikus Dittes 
Scherkl wrote:
> On Wednesday, 8 October 2014 at 01:22:49 UTC, Timon Gehr wrote:

> It doesn't matter if he uses his knowledge to open always a
> false door.

It does. Actually, this is the single most important thing.

> It only matters that you open your door AFTER him,
> which allows you to react on the result of his door. If you
> open the door first, your chance is only 1/3.

If his choice would be completely random, as you seem to suggest 
above (because, actually, its choice is conditioned by your first 
choice) then, even if you open a door after him, the only thing 
you have is the fact that you are now in problem with 50% 
probability to win.

If you remove the above piece of information, you could simply 
assume that there are only two doors and you are to open one of 
them. In this case is just 50/50.