Example #1
0
func TestTarjanSCC(t *testing.T) {
	for i, test := range tarjanTests {
		g := concrete.NewDirectedGraph(0, math.Inf(1))
		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)})
			}
		}
		gotSCCs := TarjanSCC(g)
		// tarjan.strongconnect does range iteration over maps,
		// so sort SCC members to ensure consistent ordering.
		gotIDs := make([][]int, len(gotSCCs))
		for i, scc := range gotSCCs {
			gotIDs[i] = make([]int, len(scc))
			for j, id := range scc {
				gotIDs[i][j] = id.ID()
			}
			sort.Ints(gotIDs[i])
		}
		for _, iv := range test.ambiguousOrder {
			sort.Sort(internal.BySliceValues(test.want[iv.start:iv.end]))
			sort.Sort(internal.BySliceValues(gotIDs[iv.start:iv.end]))
		}
		if !reflect.DeepEqual(gotIDs, test.want) {
			t.Errorf("unexpected Tarjan scc result for %d:\n\tgot:%v\n\twant:%v", i, gotIDs, test.want)
		}
	}
}
Example #2
0
func TestWalkAll(t *testing.T) {
	for i, test := range walkAllTests {
		g := concrete.NewGraph()

		for u, e := range test.g {
			if !g.Has(concrete.Node(u)) {
				g.AddNode(concrete.Node(u))
			}
			for v := range e {
				if !g.Has(concrete.Node(v)) {
					g.AddNode(concrete.Node(v))
				}
				g.SetEdge(concrete.Edge{F: concrete.Node(u), T: concrete.Node(v)}, 0)
			}
		}
		type walker interface {
			WalkAll(g graph.Undirected, before, after func(), during func(graph.Node))
		}
		for _, w := range []walker{
			&traverse.BreadthFirst{},
			&traverse.DepthFirst{},
		} {
			var (
				c  []graph.Node
				cc [][]graph.Node
			)
			switch w := w.(type) {
			case *traverse.BreadthFirst:
				w.EdgeFilter = test.edge
			case *traverse.DepthFirst:
				w.EdgeFilter = test.edge
			default:
				panic(fmt.Sprintf("bad walker type: %T", w))
			}
			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)

			got := make([][]int, len(cc))
			for j, c := range cc {
				ids := make([]int, len(c))
				for k, n := range c {
					ids[k] = n.ID()
				}
				sort.Ints(ids)
				got[j] = ids
			}
			sort.Sort(internal.BySliceValues(got))
			if !reflect.DeepEqual(got, test.want) {
				t.Errorf("unexpected connected components for test %d using %T:\ngot: %v\nwant:%v", i, w, got, test.want)
			}
		}
	}
}
Example #3
0
func TestConnectedComponents(t *testing.T) {
	for i, test := range connectedComponentTests {
		g := concrete.NewGraph()

		for u, e := range test.g {
			if !g.Has(concrete.Node(u)) {
				g.AddNode(concrete.Node(u))
			}
			for v := range e {
				if !g.Has(concrete.Node(v)) {
					g.AddNode(concrete.Node(v))
				}
				g.SetEdge(concrete.Edge{F: concrete.Node(u), T: concrete.Node(v)}, 0)
			}
		}
		cc := topo.ConnectedComponents(g)
		got := make([][]int, len(cc))
		for j, c := range cc {
			ids := make([]int, len(c))
			for k, n := range c {
				ids[k] = n.ID()
			}
			sort.Ints(ids)
			got[j] = ids
		}
		sort.Sort(internal.BySliceValues(got))
		if !reflect.DeepEqual(got, test.want) {
			t.Errorf("unexpected connected components for test %d %T:\ngot: %v\nwant:%v", i, g, got, test.want)
		}
	}
}
Example #4
0
func TestBronKerbosch(t *testing.T) {
	for i, test := range bronKerboschTests {
		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)
			}
		}
		cliques := topo.BronKerbosch(g)
		got := make([][]int, len(cliques))
		for j, c := range cliques {
			ids := make([]int, len(c))
			for k, n := range c {
				ids[k] = n.ID()
			}
			sort.Ints(ids)
			got[j] = ids
		}
		sort.Sort(internal.BySliceValues(got))
		if !reflect.DeepEqual(got, test.want) {
			t.Errorf("unexpected cliques for test %d:\ngot: %v\nwant:%v", i, got, test.want)
		}
	}
}
Example #5
0
func TestCyclesIn(t *testing.T) {
	for i, test := range cyclesInTests {
		g := simple.NewDirectedGraph(0, math.Inf(1))
		g.AddNode(simple.Node(-10)) // Make sure we test graphs with sparse IDs.
		for u, e := range test.g {
			// Add nodes that are not defined by an edge.
			if !g.Has(simple.Node(u)) {
				g.AddNode(simple.Node(u))
			}
			for v := range e {
				g.SetEdge(simple.Edge{F: simple.Node(u), T: simple.Node(v)})
			}
		}
		cycles := CyclesIn(g)
		var got [][]int
		if cycles != nil {
			got = make([][]int, len(cycles))
		}
		// johnson.circuit does range iteration over maps,
		// so sort to ensure consistent ordering.
		for j, c := range cycles {
			ids := make([]int, len(c))
			for k, n := range c {
				ids[k] = n.ID()
			}
			got[j] = ids
		}
		sort.Sort(internal.BySliceValues(got))
		if !reflect.DeepEqual(got, test.want) {
			t.Errorf("unexpected johnson result for %d:\n\tgot:%#v\n\twant:%#v", i, got, test.want)
		}
	}
}
Example #6
0
func TestDijkstraAllPaths(t *testing.T) {
	for _, test := range shortestPathTests {
		g := test.g()
		for _, e := range test.edges {
			g.SetEdge(e, e.Cost)
		}

		var (
			pt path.AllShortest

			panicked bool
		)
		func() {
			defer func() {
				panicked = recover() != nil
			}()
			pt = path.DijkstraAllPaths(g.(graph.Graph))
		}()
		if panicked || test.negative {
			if !test.negative {
				t.Errorf("%q: unexpected panic", test.name)
			}
			if !panicked {
				t.Errorf("%q: expected panic for negative edge weight", test.name)
			}
			continue
		}

		// Check all random paths returned are OK.
		for i := 0; i < 10; i++ {
			p, weight, unique := pt.Between(test.query.From(), test.query.To())
			if weight != test.weight {
				t.Errorf("%q: unexpected weight from Between: got:%f want:%f",
					test.name, weight, test.weight)
			}
			if weight := pt.Weight(test.query.From(), test.query.To()); weight != test.weight {
				t.Errorf("%q: unexpected weight from Weight: got:%f want:%f",
					test.name, weight, test.weight)
			}
			if unique != test.unique {
				t.Errorf("%q: unexpected number of paths: got: unique=%t want: unique=%t",
					test.name, unique, test.unique)
			}

			var got []int
			for _, n := range p {
				got = append(got, n.ID())
			}
			ok := len(got) == 0 && len(test.want) == 0
			for _, sp := range test.want {
				if reflect.DeepEqual(got, sp) {
					ok = true
					break
				}
			}
			if !ok {
				t.Errorf("%q: unexpected shortest path:\ngot: %v\nwant from:%v",
					test.name, p, test.want)
			}
		}

		np, weight, unique := pt.Between(test.none.From(), test.none.To())
		if np != nil || !math.IsInf(weight, 1) || unique != false {
			t.Errorf("%q: unexpected path:\ngot: path=%v weight=%f unique=%t\nwant:path=<nil> weight=+Inf unique=false",
				test.name, np, weight, unique)
		}

		paths, weight := pt.AllBetween(test.query.From(), test.query.To())
		if weight != test.weight {
			t.Errorf("%q: unexpected weight from Between: got:%f want:%f",
				test.name, weight, test.weight)
		}

		var got [][]int
		if len(paths) != 0 {
			got = make([][]int, len(paths))
		}
		for i, p := range paths {
			for _, v := range p {
				got[i] = append(got[i], v.ID())
			}
		}
		sort.Sort(internal.BySliceValues(got))
		if !reflect.DeepEqual(got, test.want) {
			t.Errorf("testing %q: unexpected shortest paths:\ngot: %v\nwant:%v",
				test.name, got, test.want)
		}

		nps, weight := pt.AllBetween(test.none.From(), test.none.To())
		if nps != nil || !math.IsInf(weight, 1) {
			t.Errorf("%q: unexpected path:\ngot: paths=%v weight=%f\nwant:path=<nil> weight=+Inf",
				test.name, nps, weight)
		}
	}
}
Example #7
0
func TestJohnsonAllPaths(t *testing.T) {
	for _, test := range testgraphs.ShortestPathTests {
		g := test.Graph()
		for _, e := range test.Edges {
			g.SetEdge(e)
		}

		pt, ok := JohnsonAllPaths(g.(graph.Graph))
		if test.HasNegativeCycle {
			if ok {
				t.Errorf("%q: expected negative cycle", test.Name)
			}
			continue
		}
		if !ok {
			t.Fatalf("%q: unexpected negative cycle", test.Name)
		}

		// Check all random paths returned are OK.
		for i := 0; i < 10; i++ {
			p, weight, unique := pt.Between(test.Query.From(), test.Query.To())
			if weight != test.Weight {
				t.Errorf("%q: unexpected weight from Between: got:%f want:%f",
					test.Name, weight, test.Weight)
			}
			if weight := pt.Weight(test.Query.From(), test.Query.To()); weight != test.Weight {
				t.Errorf("%q: unexpected weight from Weight: got:%f want:%f",
					test.Name, weight, test.Weight)
			}
			if unique != test.HasUniquePath {
				t.Errorf("%q: unexpected number of paths: got: unique=%t want: unique=%t",
					test.Name, unique, test.HasUniquePath)
			}

			var got []int
			for _, n := range p {
				got = append(got, n.ID())
			}
			ok := len(got) == 0 && len(test.WantPaths) == 0
			for _, sp := range test.WantPaths {
				if reflect.DeepEqual(got, sp) {
					ok = true
					break
				}
			}
			if !ok {
				t.Errorf("%q: unexpected shortest path:\ngot: %v\nwant from:%v",
					test.Name, p, test.WantPaths)
			}
		}

		np, weight, unique := pt.Between(test.NoPathFor.From(), test.NoPathFor.To())
		if np != nil || !math.IsInf(weight, 1) || unique != false {
			t.Errorf("%q: unexpected path:\ngot: path=%v weight=%f unique=%t\nwant:path=<nil> weight=+Inf unique=false",
				test.Name, np, weight, unique)
		}

		paths, weight := pt.AllBetween(test.Query.From(), test.Query.To())
		if weight != test.Weight {
			t.Errorf("%q: unexpected weight from Between: got:%f want:%f",
				test.Name, weight, test.Weight)
		}

		var got [][]int
		if len(paths) != 0 {
			got = make([][]int, len(paths))
		}
		for i, p := range paths {
			for _, v := range p {
				got[i] = append(got[i], v.ID())
			}
		}
		sort.Sort(internal.BySliceValues(got))
		if !reflect.DeepEqual(got, test.WantPaths) {
			t.Errorf("testing %q: unexpected shortest paths:\ngot: %v\nwant:%v",
				test.Name, got, test.WantPaths)
		}

		nps, weight := pt.AllBetween(test.NoPathFor.From(), test.NoPathFor.To())
		if nps != nil || !math.IsInf(weight, 1) {
			t.Errorf("%q: unexpected path:\ngot: paths=%v weight=%f\nwant:path=<nil> weight=+Inf",
				test.Name, nps, weight)
		}
	}
}