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@gsong
Last active December 11, 2016 21:05
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Christmas gift exchange
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from random import sample
# people grouped together cannot gift to each other
people = [
('Sue', 'Sam'),
('Heather', 'Matt'),
('Noelle', 'George'),
]
gifters = set([p for group in people for p in group])
def my_group(person):
for group in people:
if person in group:
return group
def gifter_for(person, pairs):
for k, v in pairs.items():
if v == person:
return k
return None
def remaining_recipients(gifter, gifters, pairs):
group = my_group(gifter)
possible_recipients = gifters - set(group) - set(pairs.values())
giver = gifter_for(gifter, pairs)
if giver:
possible_recipients -= {giver}
return possible_recipients
def pair_up(gifters):
pairs = {}
for gifter in gifters:
possible_recipients = remaining_recipients(gifter, gifters, pairs)
try:
recipient = sample(possible_recipients, 1)[0]
except ValueError:
pairs = {}
break
pairs[gifter] = recipient
if pairs:
return pairs
else:
print('Try again...')
pairs = pair_up(gifters)
return pairs
def main():
pairs = pair_up(gifters)
for k, v in pairs.items():
print("{} → {}".format(k, v))
if __name__ == '__main__':
main()
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