diff options
Diffstat (limited to 'mrbgems/mruby-array-ext/mrblib/array.rb')
| -rw-r--r-- | mrbgems/mruby-array-ext/mrblib/array.rb | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/mrbgems/mruby-array-ext/mrblib/array.rb b/mrbgems/mruby-array-ext/mrblib/array.rb index d04c11e64..1722a3631 100644 --- a/mrbgems/mruby-array-ext/mrblib/array.rb +++ b/mrbgems/mruby-array-ext/mrblib/array.rb @@ -943,4 +943,77 @@ class Array result end + + ## + # call-seq: + # ary.repeated_combination(n) { |combination| ... } -> self + # ary.repeated_combination(n) -> enumerator + # + # A +combination+ method that contains the same elements. + def repeated_combination(n, &block) + raise TypeError, "no implicit conversion into Integer" unless 0 <=> n + return to_enum(:repeated_combination, n) unless block + __repeated_combination(n, false, &block) + end + + ## + # call-seq: + # ary.repeated_permutation(n) { |permutation| ... } -> self + # ary.repeated_permutation(n) -> enumerator + # + # A +permutation+ method that contains the same elements. + def repeated_permutation(n, &block) + raise TypeError, "no implicit conversion into Integer" unless 0 <=> n + return to_enum(:repeated_permutation, n) unless block + __repeated_combination(n, true, &block) + end + + def __repeated_combination(n, permutation, &block) + case n + when 0 + yield [] + when 1 + i = 0 + while i < self.size + yield [self[i]] + i += 1 + end + else + if n > 0 + v = [0] * n + while true + tmp = [nil] * n + i = 0 + while i < n + tmp[i] = self[v[i]] + i += 1 + end + + yield tmp + + tmp = self.size + i = n - 1 + while i >= 0 + v[i] += 1 + break if v[i] < tmp + i -= 1 + end + break unless v[0] < tmp + i = 1 + while i < n + unless v[i] < tmp + if permutation + v[i] = 0 + else + v[i] = v[i - 1] + end + end + i += 1 + end + end + end + end + + self + end end |