This one was very funny! :D
I tried different method but the logic suggested by adi92 (card + prize) is the one that works better than any other I tried.
It works like this:
- a guy arrives and examines all the tables
- for each table with free seats he counts how many people he has to meet yet, then choose the one with more unknown people
- if two tables have an equal number of unknown people then the guy will choose the one with more free seats, so that there is more probability to meet more new people
at each turn the order of the people taking seats is random (this avoid possible infinite loops), this is a "demo" of the working algorithm in python:
import random
class Person(object):
def __init__(self, name):
self.name = name
self.known_people = dict()
def meets(self, a_guy, propagation = True):
"self meets a_guy, and a_guy meets self"
if a_guy not in self.known_people:
self.known_people[a_guy] = 1
else:
self.known_people[a_guy] += 1
if propagation: a_guy.meets(self, False)
def points(self, table):
"Calculates how many new guys self will meet at table"
return len([p for p in table if p not in self.known_people])
def chooses(self, tables, n_seats):
"Calculate what is the best table to sit at, and return it"
points = 0
free_seats = 0
ret = random.choice([t for t in tables if len(t)<n_seats])
for table in tables:
tmp_p = self.points(table)
tmp_s = n_seats - len(table)
if tmp_s == 0: continue
if tmp_p > points or (tmp_p == points and tmp_s > free_seats):
ret = table
points = tmp_p
free_seats = tmp_s
return ret
def __str__(self):
return self.name
def __repr__(self):
return self.name
def Switcher(n_seats, people):
"""calculate how many tables and what switches you need
assuming each table has n_seats seats"""
n_people = len(people)
n_tables = n_people/n_seats
switches = []
while not all(len(g.known_people) == n_people-1 for g in people):
tables = [[] for t in xrange(n_tables)]
random.shuffle(people) # need to change "starter"
for the_guy in people:
table = the_guy.chooses(tables, n_seats)
tables.remove(table)
for guy in table:
the_guy.meets(guy)
table += [the_guy]
tables += [table]
switches += [tables]
return switches
lst_people = [Person('Hallis'),
Person('adi92'),
Person('ilya n.'),
Person('m_oLogin'),
Person('Andrea'),
Person('1800 INFORMATION'),
Person('starblue'),
Person('regularfry')]
s = Switcher(4, lst_people)
print "You need %d tables and %d turns" % (len(s[0]), len(s))
turn = 1
for tables in s:
print 'Turn #%d' % turn
turn += 1
tbl = 1
for table in tables:
print ' Table #%d - '%tbl, table
tbl += 1
print '\n'
This will output something like:
You need 2 tables and 3 turns
Turn #1
Table #1 - [1800 INFORMATION, Hallis, m_oLogin, Andrea]
Table #2 - [adi92, starblue, ilya n., regularfry]
Turn #2
Table #1 - [regularfry, starblue, Hallis, m_oLogin]
Table #2 - [adi92, 1800 INFORMATION, Andrea, ilya n.]
Turn #3
Table #1 - [m_oLogin, Hallis, adi92, ilya n.]
Table #2 - [Andrea, regularfry, starblue, 1800 INFORMATION]
Because of the random it won't always come with the minimum number of switch, especially with larger sets of people. You should then run it a couple of times and get the result with less turns (so you do not stress all the people at the party :P ), and it is an easy thing to code :P
PS:
Yes, you can save the prize money :P