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try:
from math import gcd
except ImportError:
from fractions import gcd
# python2 workaround for python3 nonlocal keyword
class Store:
__slots__ = ('index', 'weight')
def __init__(self, index, weight):
self.index = index
self.weight = weight
def weighted(dataset):
current = Store(index=-1, weight=0)
dataset_length = len(dataset)
dataset_max_weight = 0
dataset_gcd_weight = 0
for _, weight in dataset:
if dataset_max_weight < weight:
dataset_max_weight = weight
dataset_gcd_weight = gcd(dataset_gcd_weight, weight)
def get_next():
while True:
current.index = (current.index + 1) % dataset_length
if current.index == 0:
current.weight = current.weight - dataset_gcd_weight
if current.weight <= 0:
current.weight = dataset_max_weight
if current.weight == 0:
return None
if dataset[current.index][1] >= current.weight:
return dataset[current.index][0]
return get_next
|
