// output of ./demo/comb/perm-st-pref-demo.cc:
// Description:
//% Single track ordering for permutations, swaps in prefix, CAT algorithm.

arg 1: 4 == n  [Number of elements to permute]  default=4
   0:    [ . 1 2 3 ]    [ . 1 2 3 ]    [ . . . ]
   1:    [ 1 . 2 3 ]    [ 1 . 2 3 ]    [ 1 . . ]    0: (0,1)
   2:    [ 2 . 1 3 ]    [ 1 2 . 3 ]    [ . 1 . ]    1: (1,2)
   3:    [ 2 1 . 3 ]    [ 2 1 . 3 ]    [ 1 1 . ]    0: (0,1)
   4:    [ 1 2 . 3 ]    [ 2 . 1 3 ]    [ . 2 . ]    1: (1,2)
   5:    [ . 2 1 3 ]    [ . 2 1 3 ]    [ 1 2 . ]    0: (0,1)
   6:    [ 1 3 . 2 ]    [ 2 . 3 1 ]    [ . . 1 ]    2: (0,1) (2,3)
   7:    [ . 3 1 2 ]    [ . 2 3 1 ]    [ 1 . 1 ]    0: (0,1)
   8:    [ . 3 2 1 ]    [ . 3 2 1 ]    [ . 1 1 ]    1: (1,2)
   9:    [ 1 3 2 . ]    [ 3 . 2 1 ]    [ 1 1 1 ]    0: (0,1)
  10:    [ 2 3 1 . ]    [ 3 2 . 1 ]    [ . 2 1 ]    1: (1,2)
  11:    [ 2 3 . 1 ]    [ 2 3 . 1 ]    [ 1 2 1 ]    0: (0,1)
  12:    [ 3 2 1 . ]    [ 3 2 1 . ]    [ . . 2 ]    2: (0,1) (2,3)
  13:    [ 3 2 . 1 ]    [ 2 3 1 . ]    [ 1 . 2 ]    0: (0,1)
  14:    [ 3 1 . 2 ]    [ 2 1 3 . ]    [ . 1 2 ]    1: (1,2)
  15:    [ 3 . 1 2 ]    [ 1 2 3 . ]    [ 1 1 2 ]    0: (0,1)
  16:    [ 3 . 2 1 ]    [ 1 3 2 . ]    [ . 2 2 ]    1: (1,2)
  17:    [ 3 1 2 . ]    [ 3 1 2 . ]    [ 1 2 2 ]    0: (0,1)
  18:    [ 2 . 3 1 ]    [ 1 3 . 2 ]    [ . . 3 ]    2: (0,1) (2,3)
  19:    [ 2 1 3 . ]    [ 3 1 . 2 ]    [ 1 . 3 ]    0: (0,1)
  20:    [ 1 2 3 . ]    [ 3 . 1 2 ]    [ . 1 3 ]    1: (1,2)
  21:    [ . 2 3 1 ]    [ . 3 1 2 ]    [ 1 1 3 ]    0: (0,1)
  22:    [ . 1 3 2 ]    [ . 1 3 2 ]    [ . 2 3 ]    1: (1,2)
  23:    [ 1 . 3 2 ]    [ 1 . 3 2 ]    [ 1 2 3 ]    0: (0,1)
 ct=24
