This is a modeling problem in Interger programming. We have a problem that dealt with different cities—some city that have factories that made an item and others that didn’t have factories. There are specific capacities on each of the routes between cities (“number of trains”). Each city had a demand of the items that had to be fulfilled. Items could be shipped to cities that are not adjacent as well (with a connection through another city/cities). We had to find a way fulfill these constraints that minimized the cost of transportation. Solution In order to approach these problems with no data, there will be demand of different items Let us suppose there are 3 items I1,I2,I3 and demands of which are D1,D2 and D3 Then the demands of all the three items must be fulfilled, items can be shipped from other cities i.e. D1 can send an item through D3, if there exists a path from D1 to D3 by connecting over other cities Please provide the constraints.