The only data needed for this problem is the cost of transporting the commodity per unit
from each source i to each sink} (Ci), the availability of the commodity in source i, ai,
and the demand of sink}, bj . Xij represents the amount shipped from source i to sink}.
m denotes the number of sources while n denotes the number of sinks. Notice that the
number of constraints of the transportation problem is m+n while the number of variables
is mn. The first set of constraints (2.2) comes from the fact that the sum of the shipments
from source i to all the destinations is equal to the supply available in source i. The
second set of constraints (2.3) follows similarly, by considering the sum of the shipments
from all the sources to destination}.