There are 7 (this could be optional maybe) hostages. They will be jailed into 7 rooms and they cannot communicate during this time. They can discuss 1 hour before they get jailed. They know that the will be choosen randomly every day to go into an 8th room, where the can turn on and off a light.

When someone can say surly that every hostage was a least once in this room, they are all released.

At the beginning the light is turned off.


Every hostage has a week, so there are anz_host weeks as a minimum to free the hostages. If a hostages get’s into the anz_host++ room, he/she turn’s on the light.

Everybody who comes in this week after the turn up of the light happens in the room, knows that the hostage week_num has been in the room. Maybe it get’s more evective if I use a larger window than a week, because then, the chance that more other hostages sees who’s got in the room is larger, but the time will grew up a lot.

Well let’s give it a try.

btw: You have to watch carfully which hostage knows what…


See pastie for the complete code


I tried my program on Windows and Linux (just to get better results, because of the random number implemention and the time function, be careful if you want to port the code, the obove should work well with windows)

My solution seems to be ok, an average of 90 days with the basic set. But as you can see there are a lot of option to change the basic set and then my solution still works well.

Use the option -H or /? to get help with the options.

PS: I’m not yet good at the effective programming and I’m sure there is an easier way to do things I did in my code. Feel free to tell me what you think (via mail until my comment system works)

PPS: Special thanks to my brother Dani (www.swissbytes.de), who gave me the idea to this problem and wrote a perl script to simulate his solution (well he wasn’t that successful, because his average is about 500 days I think and surly his script ran much slower than my fast C application ;) )


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