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# File 'lib/partitions/integer_partitions.rb', line 3
def partitions
n = self
raise ArgumentError, "n should be greater than or equal to 0" if n < 0
if n.zero?
if block_given?
yield []
else
p []
end
return
end
a = Array.new(n + 1, 0)
k = 2
a[1] = 0
a[2] = n
while k != 1 do
y = a[k] - 1
k -= 1
x = a[k] + 1
while x <= y do
a[k] = x
y -= x
k += 1
end
a[k] = x + y
if block_given?
yield a.values_at(1..k)
else
p a.values_at(1..k)
end
end
end
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