func TestAStar(t *testing.T) {
for _, test := range aStarTests {
pt, _ := AStar(simple.Node(test.s), simple.Node(test.t), test.g, test.heuristic)
p, cost := pt.To(simple.Node(test.t))
if !topo.IsPathIn(test.g, p) {
t.Error("got path that is not path in input graph for %q", test.name)
}
bfp, ok := BellmanFordFrom(simple.Node(test.s), test.g)
if !ok {
t.Fatalf("unexpected negative cycle in %q", test.name)
}
if want := bfp.WeightTo(simple.Node(test.t)); cost != want {
t.Errorf("unexpected cost for %q: got:%v want:%v", test.name, cost, want)
}
var got = make([]int, 0, len(p))
for _, n := range p {
got = append(got, n.ID())
}
if test.wantPath != nil && !reflect.DeepEqual(got, test.wantPath) {
t.Errorf("unexpected result for %q:\ngot: %v\nwant:%v", test.name, got, test.wantPath)
}
}
}
func TestIsPath(t *testing.T) {
dg := concrete.NewDirectedGraph()
if !topo.IsPathIn(dg, nil) {
t.Error("IsPath returns false on nil path")
}
p := []graph.Node{concrete.Node(0)}
if topo.IsPathIn(dg, p) {
t.Error("IsPath returns true on nonexistant node")
}
dg.AddNode(p[0])
if !topo.IsPathIn(dg, p) {
t.Error("IsPath returns false on single-length path with existing node")
}
p = append(p, concrete.Node(1))
dg.AddNode(p[1])
if topo.IsPathIn(dg, p) {
t.Error("IsPath returns true on bad path of length 2")
}
dg.SetEdge(concrete.Edge{p[0], p[1]}, 1)
if !topo.IsPathIn(dg, p) {
t.Error("IsPath returns false on correct path of length 2")
}
p[0], p[1] = p[1], p[0]
if topo.IsPathIn(dg, p) {
t.Error("IsPath erroneously returns true for a reverse path")
}
p = []graph.Node{p[1], p[0], concrete.Node(2)}
dg.SetEdge(concrete.Edge{p[1], p[2]}, 1)
if !topo.IsPathIn(dg, p) {
t.Error("IsPath does not find a correct path for path > 2 nodes")
}
ug := concrete.NewGraph()
ug.SetEdge(concrete.Edge{p[1], p[0]}, 1)
ug.SetEdge(concrete.Edge{p[1], p[2]}, 1)
if !topo.IsPathIn(dg, p) {
t.Error("IsPath does not correctly account for undirected behavior")
}
}
func main() {
// graph G {
G := NewGraphNode(0)
// e
e := NewGraphNode(1)
// subgraph clusterA {
clusterA := NewGraphNode(2)
// a -- b
a := NewGraphNode(3)
b := NewGraphNode(4)
a.AddNeighbor(b)
b.AddNeighbor(a)
clusterA.AddRoot(a)
clusterA.AddRoot(b)
// subgraph clusterC {
clusterC := NewGraphNode(5)
// C -- D
C := NewGraphNode(6)
D := NewGraphNode(7)
C.AddNeighbor(D)
D.AddNeighbor(C)
clusterC.AddRoot(C)
clusterC.AddRoot(D)
// }
clusterA.AddRoot(clusterC)
// }
// subgraph clusterB {
clusterB := NewGraphNode(8)
// d -- f
d := NewGraphNode(9)
f := NewGraphNode(10)
d.AddNeighbor(f)
f.AddNeighbor(d)
clusterB.AddRoot(d)
clusterB.AddRoot(f)
// }
// d -- D
d.AddNeighbor(D)
D.AddNeighbor(d)
// e -- clusterB
e.AddNeighbor(clusterB)
clusterB.AddNeighbor(e)
// clusterC -- clusterB
clusterC.AddNeighbor(clusterB)
clusterB.AddNeighbor(clusterC)
G.AddRoot(e)
G.AddRoot(clusterA)
G.AddRoot(clusterB)
// }
if !topo.IsPathIn(G, []graph.Node{C, D, d, f}) {
fmt.Println("Not working!")
} else {
fmt.Println("Working!")
}
}
