Insertion of unit flow to determine shortest route between node s = 1 and node t = 2.
The complete LP can be expressed as.
Notice that column Xij has exactly one "1" entry in row i and one "-I" entry in row j, a typical property of a network LP.
The optimal solution (obtained by TORA, file toraEx6.3-6.txt) is.
This solution gives the shortest route from node 1 to node 2 as 1 3 4 2, and the associated distance is z = 55 (miles).