Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/array_combs_perms.rb

Overview

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Instance Method Summary collapse

Instance Method Details

#comb_helper(head, tail, &block) ⇒ Object 



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# File 'lib/array_combs_perms.rb', line 31

def comb_helper head, tail, &block
  if tail.length == 0
    block.call(head)
  else
    tail.each_index do |i|
      t = tail.clone
      t.delete_at(i)
      comb_helper head.clone << tail[i], t, &block
    end
  end
end

#combinations(&block) ⇒ Object 



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# File 'lib/array_combs_perms.rb', line 43

def combinations &block
  comb_helper [], self, &block
end

#perm_helper(head, tail, &block) ⇒ Object 



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# File 'lib/array_combs_perms.rb', line 51

def perm_helper head, tail, &block
  block.call(head)
  t = tail.clone
  until t.empty?
    val = t.pop
    comb_helper head.clone << val, t, &block
  end
end

#permutations(&block) ⇒ Object 



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# File 'lib/array_combs_perms.rb', line 47

def permutations &block
  perm_helper [self[0]], self[1...self.length], &block
end

#to_s ⇒ Object 



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# File 'lib/array_combs_perms.rb', line 22

def to_s
  s = "["
  each_index do |i|
    s << " " + self[i].to_s
    s << ", " unless (i == self.length-1)
  end
  s << "]"
end