// output of ./demo/comb/paren-gray-rec-demo.cc:
// Description:
//% Gray code for paren strings via restricted growth strings (RGS), recursive algorithm.

arg 1: 5 == n  [Number of paren pairs]  default=5
   1:   0 0 0 0 0    1.1.1.1.1.
   2:   0 0 0 0 1    1.1.1.11..
   3:   0 0 0 1 2    1.1.111...
   4:   0 0 0 1 1    1.1.11.1..
   5:   0 0 0 1 0    1.1.11..1.
   6:   0 0 1 2 3    1.1111....
   7:   0 0 1 2 2    1.111.1...
   8:   0 0 1 2 1    1.111..1..
   9:   0 0 1 2 0    1.111...1.
  10:   0 0 1 1 0    1.11.1..1.
  11:   0 0 1 1 1    1.11.1.1..
  12:   0 0 1 1 2    1.11.11...
  13:   0 0 1 0 1    1.11..11..
  14:   0 0 1 0 0    1.11..1.1.
  15:   0 1 2 3 0    1111....1.
  16:   0 1 2 3 1    1111...1..
  17:   0 1 2 3 2    1111..1...
  18:   0 1 2 3 3    1111.1....
  19:   0 1 2 3 4    11111.....
  20:   0 1 2 2 3    111.11....
  21:   0 1 2 2 2    111.1.1...
  22:   0 1 2 2 1    111.1..1..
  23:   0 1 2 2 0    111.1...1.
  24:   0 1 2 1 0    111..1..1.
  25:   0 1 2 1 1    111..1.1..
  26:   0 1 2 1 2    111..11...
  27:   0 1 2 0 1    111...11..
  28:   0 1 2 0 0    111...1.1.
  29:   0 1 1 0 0    11.1..1.1.
  30:   0 1 1 0 1    11.1..11..
  31:   0 1 1 1 2    11.1.11...
  32:   0 1 1 1 1    11.1.1.1..
  33:   0 1 1 1 0    11.1.1..1.
  34:   0 1 1 2 0    11.11...1.
  35:   0 1 1 2 1    11.11..1..
  36:   0 1 1 2 2    11.11.1...
  37:   0 1 1 2 3    11.111....
  38:   0 1 0 1 0    11..11..1.
  39:   0 1 0 1 1    11..11.1..
  40:   0 1 0 1 2    11..111...
  41:   0 1 0 0 1    11..1.11..
  42:   0 1 0 0 0    11..1.1.1.
 ct=42
work/object=0.547619