thankx terence and tushar On Thu, Mar 3, 2011 at 3:18 PM, Terence <technic....@gmail.com> wrote:
> All but the last person could get free. > The last person tells the parity of number of RED(or BLACK) hat before > him.(and pray God's forgiveness :<) > Then the rest can tell the color of his own hat using what he sees before > him and what he/she hears from behind. > > > > > On 2011-3-3 16:18, freecoder wrote: > >> You are one of 20 prisoners on death row with the execution date set >> for tomorrow. >> >> Your king is a ruthless man who likes to toy with his people's >> miseries. He comes to your cell today and tells you: >> >> “I’m gonna give you prisoners a chance to go free tomorrow. You will >> all stand in a row (queue) before the executioner and we will put a >> hat on your head, either a red or a black one. Of course you will not >> be able to see the color of your own hat; you will only be able to see >> the prisoners in front of you with their hats on; you will not be >> allowed to look back or communicate together in any way (talking, >> touching.....) >> >> (The prisoner in the back will be able to see the 19 prisoners in >> front of him >> The one in front of him will be able to see 18…) >> >> Starting with the last person in the row, the one who can see >> everybody in front of him, he will be asked a simple question: WHAT IS >> THE COLOR OF YOUR HAT? >> >> He will be only allowed to answer “BLACK” or “RED”. If he says >> anything else you will ALL be executed immediately. >> >> If he guesses the right color of the hat on his head he is set free, >> otherwise he is put to death. And we move on to the one in front of >> him and ask him the same question and so on… >> >> Well, good luck tomorrow, HA HA HA HA HA HA!” >> >> Now since you all can communicate freely during the night, can you >> find a way to guarantee the freedom of some prisoners tomorrow? How >> many? >> >> > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algogeeks@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
