c 9th DIMACS Implementation Challenge: Shortest Paths c http://www.dis.uniroma1.it/~challenge9 c Sample graph file c p sp 6 8 c graph contains 6 nodes and 8 arcs c node ids are numbers in 1..6 c a 1 2 17 c arc from node 1 to node 2 of weight 17 c a 1 3 10 a 2 4 2 a 3 5 0 a 4 3 0 a 4 6 3 a 5 2 0 a 5 6 20