1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
|
unless Array.method_defined? :repeated_permutation
require 'backports/tools/arguments'
require 'backports/1.8.7/array/index'
class Array
# Note: Permutations are not yielded in the same order as MRI.
# This is not a bug; the spec states that the order is implementation dependent!!!
def repeated_permutation(num)
return to_enum(:repeated_permutation, num) unless block_given?
num = Backports.coerce_to_int(num)
if num <= 0
yield [] if num == 0
else
copy = dup
indices = Array.new(num, 0)
indices[-1] = size
while dec = indices.index{|x| x != 0}
indices.fill size-1, 0, dec
indices[dec] -= 1
yield copy.values_at(*indices)
end
end
self
end
end
end
|
