Roos Vahrmeijer

Output is as follows: Solved in 0.028 secs. OPTIMALObjective value: 24.075000000000003Used edges:0 1 10 4 21 6 12 5 13 7 24 3 25 7 16 2 1   Now delivery takes place before picking up

n= 3n2 = 3 P = [i for i in range (1, n+1)]D = [i for i in range (n+1,n+n2+1)]Ck = {1:6, 2:6}K = [i for i in range (1, len(Ck)+1)]N = P + Dqi = {0:0, 1:6, 2:3, 3:6, 4:-6, 5:-3, 6:-6, 7:0}di = {0:0, ...

Can share my full code with you   

Yes qi can be negative because by delivery the demand is negative and for pick up it is positive