: Prisoner Puzzle v1.0 : the solution
: Each prisoner except one, which we will call the
ring-leader, turns the light on if
: it was off. If it was on already, they leave it on. However,
they turn the light on
: exactly once - the first time they take a shower in which the
light-switch was off.
: The ring-leader is the only person who does something different.
If she finds the
: light on, she increments her counter and turns the light off.
If she finds the light off,
: she leaves it in that position.
: In this manner, each other prisoner communicates a single bit
of information to
: the ring-leader, i.e. their having had their first shower. If
: counter ever reaches 'n', then she knows that all 'n' prisoners
: have had at least one shower and can make this assertion to the
: them all free.
: Prisoner Puzzle v2.0 : the set-up
: Suppose now that the Warden sets the prisoners
an even more difficult task. In order
: to be freed, all of the prisoners
must make the assertion that they have all had at
: least one shower. This is a significantly harder problem; one
which I don't know of
: a solution for.
: Good luck!