public void BellmanFordNotReachable()
{
var run = new MoveTypeEdgeData {
moveType = MoveType.Run
};
var jump = new MoveTypeEdgeData {
moveType = MoveType.Jump
};
var wallJump = new MoveTypeEdgeData {
moveType = MoveType.WallJump
};
var myGraph = new DirectedWeightedGraph <char, MoveTypeEdgeData>();
myGraph.AddNodes('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h');
myGraph.AddEdges(
('a', 'b', 2, run),
('a', 'c', 3, run),
('a', 'e', 4, wallJump),
('b', 'd', 2, jump),
('b', 'e', 1, run),
('c', 'g', 4, jump),
('c', 'h', 11, run),
('d', 'c', 3, jump),
('d', 'h', 3, wallJump),
('f', 'd', 2, run),
('f', 'h', 6, wallJump),
('g', 'h', 7, run)
);
myGraph
.BellmanFordShortestPath('a', 'f')
.Should()
.BeEmpty();
}
public static int?[,] GetShortestPaths(DirectedWeightedGraph graph)
{
int n = graph.NodesCount;
for (int i = 0; i < n; i++)
{
graph.AddEdge(n, i, 0);
}
var weights = BellmanFord.GetShortestPaths(graph, n);
if (weights == null)
{
return null;
}
graph.RemoveNode(n);
var reweightedGraph = new DirectedWeightedGraph();
foreach (var edge in graph.GetEdges())
{
reweightedGraph.AddEdge(edge.StartNode, edge.EndNode, edge.Weight + weights[edge.StartNode].Value - weights[edge.EndNode].Value);
}
var distances = new int?[n, n];
for (int i = 0; i < n; i++)
{
int j = 0;
foreach (var distance in Dijkstra.Find(reweightedGraph, i))
{
distances[i, j] = distance - weights[i] + weights[j];
j++;
}
}
return distances;
}
public void VisitAll_ShouldCountNumberOfVisitedVertix_ResultShouldBeTheSameAsNumberOfVerticesInGraph()
{
//Arrange
var graph = new DirectedWeightedGraph <int>(10);
var vertex1 = graph.AddVertex(1);
var vertex2 = graph.AddVertex(20);
var vertex3 = graph.AddVertex(40);
var vertex4 = graph.AddVertex(40);
graph.AddEdge(vertex1, vertex2, 1);
graph.AddEdge(vertex2, vertex3, 1);
graph.AddEdge(vertex2, vertex4, 1);
graph.AddEdge(vertex4, vertex1, 1);
var dfsSearcher = new DepthFirstSearch <int>();
long countOfVisitedVertices = 0;
//Act
dfsSearcher.VisitAll(graph, vertex1, (Vertex <int> vertex) => countOfVisitedVertices++);
//Assert
Assert.AreEqual(countOfVisitedVertices, graph.Count);
}
/// <summary>
/// Implementation of the Dijkstra shortest path algorithm for cyclic graphs.
/// https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm.
/// </summary>
/// <param name="graph">Graph instance.</param>
/// <param name="startVertex">Starting vertex instance.</param>
/// <typeparam name="T">Generic Parameter.</typeparam>
/// <returns>List of distances from current vertex to all other vertices.</returns>
/// <exception cref="InvalidOperationException">Exception thrown in case when graph is null or start
/// vertex does not belong to graph instance.</exception>
public static DistanceModel <T>[] GenerateShortestPath <T>(DirectedWeightedGraph <T> graph, Vertex <T> startVertex)
{
ValidateGraphAndStartVertex(graph, startVertex);
var visitedVertices = new List <Vertex <T> >();
var distanceArray = InitializeDistanceArray(graph, startVertex);
var currentVertex = startVertex;
var currentPath = 0d;
while (true)
{
visitedVertices.Add(currentVertex);
var neighborVertices = graph
.GetNeighbors(currentVertex)
.Where(x => x != null && !visitedVertices.Contains(x))
.ToList();
foreach (var vertex in neighborVertices)
{
var adjacentDistance = graph.AdjacentDistance(currentVertex, vertex !);
var distance = distanceArray[vertex !.Index];
public void Test()
{
var graph1 = new DirectedWeightedGraph(false);
for (int i = 'a'; i <= 'h'; i++)
{
graph1.AddVertex(Convert.ToString(Convert.ToChar(i)));
}
graph1.AddEdge("a", "b", 1);
graph1.AddEdge("b", "c", 2);
graph1.AddEdge("c", "d", 3);
graph1.AddEdge("a", "g", 600);
graph1.AddEdge("b", "f", 0);
graph1.AddEdge("e", "b", 7);
Stack <Vertex> stack = new Stack <Vertex>();
stack.Push(graph1.GetVertex("d"));
stack.Push(graph1.GetVertex("c"));
stack.Push(graph1.GetVertex("f"));
stack.Push(graph1.GetVertex("b"));
stack.Push(graph1.GetVertex("g"));
stack.Push(graph1.GetVertex("a"));
stack.Push(graph1.GetVertex("e"));
stack.Push(graph1.GetVertex("h"));
var testStack = TopologicalSort <DirectedWeightedGraph> .Sort(graph1);
for (int i = 'a'; i <= 'h'; i++)
{
Assert.AreEqual(stack.Pop(), testStack.Pop());
}
}
public void Ctor_ShouldInitializeAdjacencyLists()
{
var graph = new DirectedWeightedGraph <int, int>();
Assert.NotNull(graph.AdjacencyLists);
Assert.Empty(graph.AdjacencyLists);
}
public void Ctor_ShouldInitializeAdjacencyListsWithVerticesAndEdgesWithDefaultWeights()
{
var vertices = new List <int> {
0, 1, 2
};
var edges = new List <Edge <int> >()
{
new Edge <int>(0, 1),
new Edge <int>(0, 2),
new Edge <int>(2, 0)
};
var expectedAdjacencyLists = new Dictionary <int, IReadOnlyList <int> >()
{
[0] = new List <int>()
{
1, 2
},
[1] = new List <int>()
{
},
[2] = new List <int>()
{
0
},
};
var graph = new DirectedWeightedGraph <int, int>(vertices, edges);
Assert.Equal(expectedAdjacencyLists, graph.AdjacencyLists);
Assert.All(edges, edge =>
{
Assert.Equal(default, graph.Weights[edge]);
public void DijkstraNegativeWeight()
{
var run = new MoveTypeEdgeData {
moveType = MoveType.Run
};
var jump = new MoveTypeEdgeData {
moveType = MoveType.Jump
};
var wallJump = new MoveTypeEdgeData {
moveType = MoveType.WallJump
};
var myGraph = new DirectedWeightedGraph <char, MoveTypeEdgeData>();
myGraph.AddNodes('a', 'b', 'c', 'd');
myGraph.AddEdges(
('a', 'b', -2, run),
('a', 'c', 3, run),
('b', 'd', 2, jump),
('d', 'c', -3, jump)
);
myGraph
.Invoking(x => x.DijkstraShortestPath('a', 'd').Count())
.Should()
.Throw <NegativeWeightException>();
}
public static void Main()
{
//System.IO.TextReader s = System.IO.File.OpenText("mediumEWD.txt");
System.IO.TextReader s = System.IO.File.OpenText("tinyEWDAG.txt");
DirectedWeightedGraph graph = new DirectedWeightedGraph(s);
Console.Write("请输入起点：");
int st = int.Parse(Console.ReadLine());
AcyclicSP sp = new AcyclicSP(graph, st);
for (int i = 0; i < graph.V; ++i)
{
if (i == st)
{
Console.WriteLine("{0}->{0} : 0.0", st);
continue;
}
if (!sp.HasPathTo(i))
{
Console.WriteLine("{0}->{1} : No paths", st, i);
continue;
}
Double len = 0.0;
foreach (var edge in sp.PathTo(i))
{
Console.Write(edge);
Console.Write(",");
len += edge.Weight;
}
Console.WriteLine(" : {0}", len);
}
}
public void BellmanFordSingleSourceShortestPathNegativeCycle()
{
var run = new MoveTypeEdgeData {
moveType = MoveType.Run
};
var jump = new MoveTypeEdgeData {
moveType = MoveType.Jump
};
var wallJump = new MoveTypeEdgeData {
moveType = MoveType.WallJump
};
var myGraph = new DirectedWeightedGraph <char, MoveTypeEdgeData>();
myGraph.AddNodes('a', 'b', 'c');
myGraph.AddEdges(
('a', 'b', -2, run),
('b', 'c', -3, run),
('c', 'a', -1, jump)
);
myGraph
.Invoking(x => x.BellmanFordSingleSourceShortestPath('a').Count())
.Should().
Throw <NegativeCycleException>();
}
private void FindNegtiveCycle()
{
int V = edgeTo.Length;//图的节点数量
DirectedWeightedGraph spt = new DirectedWeightedGraph(V);
for (int v = 0; v < V; ++v)
{
if (edgeTo[v] != null)
{
spt.AddEdge(edgeTo[v]);
}
}
DirectedCycle cf = new DirectedCycle(spt);
//需要转换形式
Queue <DirectedEdge> edges = new Queue <DirectedEdge>();//没有还
var list = cf.Cycle().ToList();
if (list.Count == 0)
{
return;
}
for (int i = 0; i < list.Count - 1; ++i)
{
edges.Enqueue(new DirectedEdge(list[i], list[i + 1], spt.GetWeight(list[i], list[i + 1])));
}
cycle = edges;
}
public void Relax(DirectedWeightedGraph g, int v)
{
foreach (DirectedEdge edge in g.GetEdge(v))
{
int w = edge.End;
//如果存在放松的条件
if (distTo[w] > distTo[v] + edge.Weight)
{
distTo[w] = distTo[v] + edge.Weight;
edgeTo[w] = edge;
//添加为需要继续放松的
if (this.onQueue[w] == false)
{
this.queue.Enqueue(w);
this.onQueue[w] = true;
}
}
if (cost++ % g.V == 0)//根据436 页 定理X.V 个不含有负权环图的节点，放松 V 次可以得到最短路径
{
FindNegtiveCycle();
if (HasNegativeCycle())
{
return;
}
}
}
}
public void DijkstraTest3_Success()
{
var graph = new DirectedWeightedGraph <char>(5);
var a = graph.AddVertex('A');
var b = graph.AddVertex('B');
var c = graph.AddVertex('C');
graph.AddEdge(a, b, 1);
graph.AddEdge(b, a, 1);
graph.AddEdge(a, c, 3);
graph.AddEdge(c, a, 3);
var shortestPathList = DijkstraAlgorithm.GenerateShortestPath(graph, a);
shortestPathList.Length.Should().Be(3);
shortestPathList[0].Vertex.Should().Be(a);
shortestPathList[0].Distance.Should().Be(0);
shortestPathList[0].PreviousVertex.Should().Be(a);
shortestPathList[0].ToString().Should()
.Be($"Vertex: {a} - Distance: {0} - Previous: {a}");
shortestPathList[1].Vertex.Should().Be(b);
shortestPathList[1].Distance.Should().Be(1);
shortestPathList[1].PreviousVertex.Should().Be(a);
shortestPathList[1].ToString().Should()
.Be($"Vertex: {b} - Distance: {1} - Previous: {a}");
shortestPathList[2].Vertex.Should().Be(c);
shortestPathList[2].Distance.Should().Be(3);
shortestPathList[2].PreviousVertex.Should().Be(a);
shortestPathList[2].ToString().Should()
.Be($"Vertex: {c} - Distance: {3} - Previous: {a}");
}
public void Test()
{
// orientovaný ohodnocený.
var graph1 = new DirectedWeightedGraph(false);
for (int i = 'a'; i < 'h'; i++)
{
graph1.AddVertex(Convert.ToString(Convert.ToChar(i)));
}
graph1.AddEdge("a", "b", 1);
graph1.AddEdge("b", "c", 2);
graph1.AddEdge("c", "d", 3);
graph1.AddEdge("d", "e", -4);
graph1.AddEdge("f", "c", 5);
graph1.AddEdge("a", "g", 600);
graph1.AddEdge("b", "f", 0);
graph1.AddEdge("b", "e", 7);
DepthFirstSearch <DirectedWeightedGraph> .Search(graph1, "a");
Assert.AreEqual(0, graph1.GetVertex("a").distance);
Assert.AreEqual(1, graph1.GetVertex("b").distance);
Assert.AreEqual(2, graph1.GetVertex("c").distance);
Assert.AreEqual(3, graph1.GetVertex("d").distance);
Assert.AreEqual(4, graph1.GetVertex("e").distance);
Assert.AreEqual(2, graph1.GetVertex("f").distance);
Assert.AreEqual(1, graph1.GetVertex("g").distance);
}
private double[] inw; //inw[i] 记录i入边的权值
/// <summary>
/// 构造函数
/// </summary>
/// <param name="digraph">有向图</param>
/// <param name="root">起点</param>
public ZhuLiuAlgorithmInMinimumTreeGraph(DirectedWeightedGraph digraph, int root)
{
pre = new int[digraph.V];
vis = new int[digraph.V];
id = new int[digraph.V];
inw = new double[digraph.V];
MinWeight = Solve(digraph, root);
}
public void AddNode()
{
var myGraph = new DirectedWeightedGraph <int, EdgeData>();
myGraph.AddNode(4);
myGraph.Exists(4).Should().BeTrue();
}
public void GraphRemoveVertexTest_ShouldThrowVertexNotInGraph()
{
var graph = new DirectedWeightedGraph <char>(10);
var vertexA = new Vertex <char>('A', 0);
Action removeVertex = () => graph.RemoveVertex(vertexA);
removeVertex.Should().Throw <InvalidOperationException>()
.WithMessage($"Vertex does not belong to graph: {vertexA}.");
}
public void GraphAddVertexTest_Success()
{
var graph = new DirectedWeightedGraph <char>(10);
graph.AddVertex('A');
graph.AddVertex('B');
graph.AddVertex('C');
graph.Count.Should().Be(3);
}
private Double[] distTo; // disTo[i] 保存的是从 v 到 i 的距离
/// <summary>
/// 构造函数
/// </summary>
/// <param name="g">有向加权非负权图</param>
/// <param name="s">起点</param>
public AcyclicSP(DirectedWeightedGraph g, int s)
{
edgeTo = new DirectedEdge[g.V];
distTo = new Double[g.V];
for (Int32 v = 0; v < g.V; ++v)
{
distTo[v] = Double.PositiveInfinity;
}
Topological top = new Topological(g);
}
public void DijkstraMethodTest_ShouldThrow_GraphIsNull()
{
var graph = new DirectedWeightedGraph <char>(5);
var a = graph.AddVertex('A');
Func <DistanceModel <char>[]> action = () => DijkstraAlgorithm.GenerateShortestPath(null !, a);
action.Should().Throw <ArgumentNullException>()
.WithMessage($"Value cannot be null. (Parameter '{nameof(graph)}')");
}
public void GraphAddEdgeTest_ShouldThrowZeroWeight()
{
var graph = new DirectedWeightedGraph <char>(10);
var vertexA = graph.AddVertex('A');
var vertexB = graph.AddVertex('B');
Action addZeroEdge = () => graph.AddEdge(vertexA, vertexB, 0);
addZeroEdge.Should().Throw <InvalidOperationException>()
.WithMessage("Edge weight cannot be zero.");
}
public void GraphRemoveEdgeTest_ShouldThrowVertexNotInGraph()
{
var graph = new DirectedWeightedGraph <char>(10);
var vertexA = graph.AddVertex('A');
var vertexB = new Vertex <char>('B', 1);
Action removeEdge = () => graph.RemoveEdge(vertexA, vertexB);
removeEdge.Should().Throw <InvalidOperationException>()
.WithMessage($"Vertex does not belong to graph: {vertexB}.");
}
public static void Main()
{
var sf = "criticalPath.txt";
var txr = System.IO.File.OpenText(sf);
var digrpah = new DirectedWeightedGraph(txr);
var crt = new CriticalPath(digrpah);
foreach (var p in crt.GetCriticalPaths())
{
Console.WriteLine($"活动：{p}");
}
}
public void GraphRemoveEdgeTest_Success()
{
var graph = new DirectedWeightedGraph <char>(10);
var vertexA = graph.AddVertex('A');
var vertexB = graph.AddVertex('B');
graph.AddEdge(vertexA, vertexB, 5);
graph.RemoveEdge(vertexA, vertexB);
graph.AreAdjacent(vertexA, vertexB).Should().BeFalse();
}
public void Test()
{
#region Orientovaná kružnice
// orientovaný ohodnocený.
var graph1 = new DirectedWeightedGraph(false);
for (int i = 'a'; i < 'h'; i++)
{
graph1.AddVertex(Convert.ToString(Convert.ToChar(i)));
}
graph1.AddEdge("a", "b", 1);
graph1.AddEdge("b", "c", 2);
graph1.AddEdge("c", "d", 3);
graph1.AddEdge("d", "e", -4);
graph1.AddEdge("f", "c", 5);
graph1.AddEdge("a", "g", 600);
graph1.AddEdge("b", "f", 0);
graph1.AddEdge("e", "b", 7);
Assert.IsTrue(Cycle.ContainsCycle <DirectedWeightedGraph>(graph1));
graph1.Clear();
#endregion
#region Orientovaný bez kružnice
// orientovaný ohodnocený.
var graph3 = new DirectedUnweightedGraph(false);
for (int i = 'a'; i < 'h'; i++)
{
graph3.AddVertex(Convert.ToString(Convert.ToChar(i)));
}
graph3.AddEdge("a", "b");
graph3.AddEdge("b", "c");
graph3.AddEdge("c", "d");
graph3.AddEdge("a", "g");
graph3.AddEdge("b", "f");
graph3.AddEdge("e", "b");
Assert.IsFalse(Cycle.ContainsCycle <DirectedUnweightedGraph>(graph3));
graph3.Clear();
#endregion
}
private void RunClick(object sender, RoutedEventArgs e)
{
var graph = DirectedWeightedGraph.CreateEmpty(3);
graph.AddEdge(new DirectedWeightedEdge(graph.Vertices[0], graph.Vertices[1], 2));
graph.AddEdge(new DirectedWeightedEdge(graph.Vertices[0], graph.Vertices[2], 6));
graph.Vertices[0].DisplayName = "hi";
Visualizer.Graph = graph;
//((Vertex)Visualizer.Vertices[3]).Background = new SolidColorBrush(Colors.Magenta);
//((Vertex)Visualizer.Vertices[1]).Radius = 30;
_visualizerGraphProto = graph;
((Button)sender).Visibility = Visibility.Collapsed;
}
public void AddEdge()
{
var myGraph = new DirectedWeightedGraph <int, EdgeData>();
myGraph.AddNodes(5, 6);
myGraph.AddEdge(5, 6, 10, dummyEdgeData);
myGraph.Neighbors(5).Should().Contain(6);
myGraph.Weight(5, 6).Should().Be(10);
myGraph.EdgeData(5, 6).Should().Be(dummyEdgeData);
myGraph.Invoking(x => x.AddEdge(5, 6, 3, dummyEdgeData)).Should().Throw <ArgumentException>();
}
private void Relax(DirectedWeightedGraph g, int v)
{
foreach (DirectedEdge edge in g.GetEdge(v))
{
int w = edge.End;
//如果存在放松的条件
if (distTo[w] > distTo[v] + edge.Weight)
{
distTo[w] = distTo[v] + edge.Weight;
edgeTo[w] = edge;
}
}
}
public static void Main()
{
StreamReader reader = File.OpenText("zhuliudirectedgraph.txt");
DirectedWeightedGraph graph = new DirectedWeightedGraph(reader);
foreach (DirectedEdge edge in graph)
{
Console.WriteLine(edge.Src + "->" + edge.End);
}
ZhuLiuAlgorithmInMinimumTreeGraph minimumTreeGraph = new ZhuLiuAlgorithmInMinimumTreeGraph(graph, 1);
double res = minimumTreeGraph.MinWeight;
int j = 25;
}
public void Weight()
{
var myGraph = new DirectedWeightedGraph <int, EdgeData>();
myGraph.AddNodes(1, 2, 3);
myGraph.AddEdges(
(1, 2, 4, dummyEdgeData),
(2, 3, 5, dummyEdgeData)
);
myGraph.Weight(1, 2).Should().Be(4);
myGraph.Weight(2, 3).Should().Be(5);
myGraph.Invoking(x => x.Weight(3, 4)).Should().Throw <System.ArgumentException>();
}
public BasicCompositor(ObjectManager objm, RendererContext rc)
{
graphLock = new object();
_CompositorGraph = objm.CreateOrRecycle<DirectedWeightedGraph<CompositorNode, CompositorEdgeDescriptionListWrapper>>();
_CompositorGraph.Init();
_Nodes = new List<DirectedWeightedNode<CompositorNode, CompositorEdgeDescriptionListWrapper>>();
_Edges = new List<DirectedWeightedEdge<CompositorNode, CompositorEdgeDescriptionListWrapper>>();
DummyNode = _CompositorGraph.AddNode(null);
RendererContext = rc;
}
public void GraphGetNeighborsTest_ShouldThrowVertexNotInGraph()
{
var graph = new DirectedWeightedGraph <char>(10);
var vertexA = new Vertex <char>('A', 0);
Func <List <Vertex <char>?> > getNeighbors = () =>
{
var enumerable = graph.GetNeighbors(vertexA);
return(enumerable.ToList());
};
getNeighbors.Should().Throw <InvalidOperationException>()
.WithMessage($"Vertex does not belong to graph: {vertexA}.");
}