More Puzzles

   Log inLog in 
 
 RegisterRegister Immediately 

Very Difficult Logic Problems
Coins on a Chessboard

 
Tue Aug 30, 2016 4:48 am  by tartle

A warden takes prisoner A into a room containing a chessboard, on each square of which is a coin randomly showing heads or tails. He then indicates a random square on that board. Prisoner A is given the chance to flip one coin (or none), then taken from the room, after which prisoner B is taken into the room and must say which square the warden indicated. The two prisoners may strategize beforehand, but may not communicate during the trial (except with the single coin flip). What should be their strategy?
 
   
Sun Jan 08, 2017 3:23 am  by anon

Does A turn the coin (A chooses) over or flip it by throwing it (random)?
 
   
Sun Mar 26, 2017 9:48 pm  by batze

Solution for a 2-square chessboard:

HH -> HH / TH
HT -> HH / HT
TH -> HH / TH
TT -> TT / HT

The 2 cases are:
1. both the same
2. different

And now a solution for a 3-square chessboard:

HHH -> HHH / HTH / HHT
HHT -> HHH / THT / HHT
HTH -> HHH / HTH / TTH
HTT -> TTT / HTH / HHT
THH -> HHH / THT / THH
THT -> TTT / THT / THH
TTH -> TTT / HTH / THH
TTT -> TTT / THT / TTH

Here the 3 cases are:
1. all the same
2. single outlier in the middle
3. single outlier at the border

This should be extendable to 64 squares, but the pattern rules will become more and more complicated.
 
   
Reply to topic
      All times are GMT
Page 1 of 1

 
 



Discussion Board Forum Index