On average, how large a group is required for two people to have the same birthday? I remembered the answer was lower than I expected, but I forgot what the answer was.

Stuff like that bothers me. I suck at probability theory so often use Monte Carlo method for solutions.

So who cares? If you are in a room with this number of people with nothing to do (ie network is down), bet them all a buck that two people in the room share a birthday. Then send me a buck.


#!/usr/bin/perl use strict; my $TRIALS = 1024; my $total; for (1..$TRIALS) { $total += trial(); } $total /= $TRIALS; print "$total\n"; sub trial { my (%days, $i); while (++$i) { if ($days{int(rand(365))}++) { return $i; } } }