----------------  SOLUTION  -------------------

solution cost   : 837.672
number of trips : 4

trip 1, 14 customers, sequence : 3 5 6 10 18 19 21 20 22 23 24 25 17 13 
   weight    : 7770
   volume    : 14
   trip cost : 266.662

trip 2, 8 customers, sequence : 2 12 11 32 8 9 7 4 
   weight    : 7850
   volume    : 8
   trip cost : 167.719

trip 3, 7 customers, sequence : 1 15 26 27 16 28 29 
   weight    : 7950
   volume    : 7
   trip cost : 246.859

trip 4, 3 customers, sequence : 31 14 30 
   weight    : 5800
   volume    : 3
   trip cost : 156.432