CM.make();
(* page 556 in CLR *)
functor TestAllPairsShortestPaths(AP : ALL_PAIRS_SHORTEST_PATHS
where type Num.elem = int) =
struct
val G as Graph.GRAPH g = DirectedGraph.graph("foo",(),10) :
(string,int,unit) Graph.graph
val _ = app (#add_node g)
[(1,"1"),
(2,"2"),
(3,"3"),
(4,"4"),
(5,"5")
]
val E = [(1,2,3),
(1,3,8),
(1,5,~4),
(2,4,1),
(2,5,7),
(3,2,4),
(4,1,2),
(4,3,~5),
(5,4,6)
]
val _ = app (#add_edge g) E
(* val _ = app (fn (i,j,w) => #add_edge g (j,i,w)) E *)
val dist' = [[0,1,~3,2,~4],
[3,0,~4,1,~1],
[7,4,0,5,3],
[2,~1,~5,0,~2],
[8,5,1,6,0]
]
val pred' = [[~1,3,4,5,1],
[4,~1,4,2,1],
[4,3,~1,2,1],
[4,3,4,~1,1],
[4,3,4,5,~1]
]
fun toList M =
let val N = 5
fun f(i,j) = if j > N then [] else Array2.sub(M,i,j)::f(i,j+1)
fun g(i) = if i > N then [] else f(i,1)::g(i+1)
in g 1
end
fun test() =
let fun weight(_,_,w) = w
val {dist,pred} = AP.all_pairs_shortest_paths {graph=G,weight=weight}
val dist=toList dist
val pred=toList pred
in if dist <> dist' orelse pred <> pred' then raise Match else ();
{dist=dist,pred=pred}
end
end
structure TestWarshall = TestAllPairsShortestPaths(
FloydWarshallFn(struct type elem = int
open Int
val zero = 0
val == : int * int -> bool = op =
val inf = 100000000
end))
structure TestJohnson = TestAllPairsShortestPaths(
JohnsonFn(struct type elem = int
open Int
val zero = 0
val == : int * int -> bool = op =
val inf = 100000000
end))