struct a six customer (city) vehicle routing problem. The depot is denoted 0 (zero) and the distance matrix is given in table. 0 6 0 1 4 5 2 3 S 20 18 14 16 12 19 1 20 - 22 18 30 26 28 2 18 22 32 20 22 21 3 14 18 32 482 - 20 22 21 4 16 30 20 20 30 32 5 12 26 22 22 30 26 6 19 28 21 21 32 26 a) Construct the above VRP as a traveling salesman problem that minimizes the distance with 4 vehicles. (7 marks) b) Construct the above VRP as a traveling salesman problem that minimizes the distance with a minimum number of vehicles. (3 marks)