func TestDepthFirst(t *testing.T) {
for i, test := range depthFirstTests {
g := concrete.NewGraph()
for u, e := range test.g {
// Add nodes that are not defined by an edge.
if !g.Has(concrete.Node(u)) {
g.AddNode(concrete.Node(u))
}
for v := range e {
g.SetEdge(concrete.Edge{F: concrete.Node(u), T: concrete.Node(v)}, 0)
}
}
w := traverse.DepthFirst{
EdgeFilter: test.edge,
}
var got []int
final := w.Walk(g, test.from, func(n graph.Node) bool {
if test.until != nil && test.until(n) {
return true
}
got = append(got, n.ID())
return false
})
if !test.final[final] {
t.Errorf("unexepected final node for test %d:\ngot: %v\nwant: %v", i, final, test.final)
}
sort.Ints(got)
if test.want != nil && !reflect.DeepEqual(got, test.want) {
t.Errorf("unexepected DFS traversed nodes for test %d:\ngot: %v\nwant: %v", i, got, test.want)
}
}
}
// ConnectedComponents returns the connected components of the undirected graph g.
func ConnectedComponents(g graph.Undirected) [][]graph.Node {
var (
w traverse.DepthFirst
c []graph.Node
cc [][]graph.Node
)
during := func(n graph.Node) {
c = append(c, n)
}
after := func() {
cc = append(cc, []graph.Node(nil))
cc[len(cc)-1] = append(cc[len(cc)-1], c...)
c = c[:0]
}
w.WalkAll(g, nil, after, during)
return cc
}