subroutine tsp_dantzig42_order ( dantzig42_order )

c*********************************************************************72
c
cc tsp_dantzig42_order() returns the ordering for the Dantzig 42 city TSP challenge.
c
c  Licensing:
c
c    This code is distributed under the MIT license.
c
c  Modified:
c
c    15 July 2026
c
c  Author:
c
c    John Burkardt
c
c  Output:
c
c    integer dantzig42_order[42]: the 1-based optimal tour order.
c
      implicit none

      integer dantzig42_order(42)

      dantzig42_order = (/ 
     &  42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 
     &  32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 
     &  22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 
     &  12, 11, 10,  9,  8,  7,  6,  5,  4,  3, 
     &   2,  1 /)

      return
      end
      subroutine tsp_dantzig42_xy ( dantzig42_xy )

c*********************************************************************72
c
cc tsp_dantzig42_xy() returns the locations for the Dantzig 42 city TSP challenge.
c
c  Discussion:
c
c    The original values 
c
c     147.5,  36.0,
c     154.5,  45.0,
c
c    were adjusted to 
c
c     147.0,  36.0,
c     154.0,  45.0,
c
c    so that all coordinates are integers.
c
c  Licensing:
c
c    This code is distributed under the MIT license.
c
c  Modified:
c
c    21 July 2026
c
c  Author:
c
c    John Burkardt
c
c  Output:
c
c    double precision tsp_dantzig42_xy(42,2): the x and y coordinates of the cities.
c
      implicit none

      double precision dantzig42_xy(42,2)
c
c  Excuse this monstrous "tranpose(reshape())", caused by the fact that
c  the data is by rows, but Fortran prefers columns.
c
      dantzig42_xy = transpose ( reshape ( (/ 
     & 170.0,  85.0, 
     & 166.0,  88.0, 
     & 133.0,  73.0, 
     & 140.0,  70.0, 
     & 142.0,  55.0, 
     & 126.0,  53.0, 
     & 125.0,  60.0, 
     & 119.0,  68.0, 
     & 117.0,  74.0, 
     &  99.0,  83.0, 
     &  73.0,  79.0, 
     &  72.0,  91.0, 
     &  37.0,  94.0, 
     &   6.0, 106.0, 
     &   3.0,  97.0, 
     &  21.0,  82.0, 
     &  33.0,  67.0, 
     &   4.0,  66.0, 
     &   3.0,  42.0, 
     &  27.0,  33.0, 
     &  52.0,  41.0, 
     &  57.0,  59.0, 
     &  58.0,  66.0, 
     &  88.0,  65.0, 
     &  99.0,  67.0, 
     &  95.0,  55.0, 
     &  89.0,  55.0, 
     &  83.0,  38.0, 
     &  85.0,  25.0, 
     & 104.0,  35.0, 
     & 112.0,  37.0, 
     & 112.0,  24.0, 
     & 113.0,  13.0, 
     & 125.0,  30.0, 
     & 135.0,  32.0, 
     & 147.0,  18.0, 
     & 147.0,  36.0, 
     & 154.0,  45.0, 
     & 157.0,  54.0, 
     & 158.0,  61.0, 
     & 172.0,  82.0, 
     & 174.0,  87.0 /), (/ 2,42 /) ) )

      return
      end