public static int ComputeShortestPath(IDirectedGraph <int> graph, int startVertex, int endVertex)
{
if (startVertex == endVertex)
{
return(0);
}
// Key - Node, Value - node distance from startVertex
var exploredVertices = new Dictionary <int, int> {
{ startVertex, 0 }
};
var queue = new Queue <int>();
queue.Enqueue(startVertex);
while (queue.Any())
{
int v = queue.Dequeue();
foreach (int w in graph.GetAdjacentVertices(v))
{
if (!exploredVertices.ContainsKey(w))
{
int dist = exploredVertices[v] + 1;
exploredVertices.Add(w, dist);
queue.Enqueue(w);
}
}
}
return(exploredVertices.ContainsKey(endVertex) ? exploredVertices[endVertex] : int.MinValue);
}
private static void DfsFindSccs(IDirectedGraph <int> graph,
int startVertex,
HashSet <int> exploredVertices,
List <int> sccs)
{
var stack = new Stack <int>();
stack.Push(startVertex);
while (stack.Any())
{
int v = stack.Peek();
if (!exploredVertices.Contains(v))
{
exploredVertices.Add(v);
}
bool hasUnexploredNeighbours = false;
foreach (int w in graph.GetAdjacentVertices(v))
{
if (!exploredVertices.Contains(w))
{
hasUnexploredNeighbours = true;
stack.Push(w);
break;
}
}
if (!hasUnexploredNeighbours)
{
sccs.Add(stack.Pop());
}
}
}
/// <summary>
/// Implementacija Bellman-Ford algoritma za pronalazenje najkracih putanja u
/// tezinskom, orijentisanom ili neorijentisanom grafu sa ili bez ciklusa.
/// </summary>
/// <param name="graph"></param>
/// <param name="start"></param>
/// <returns>true u slucaju da je pronadjeno negativno pojacanje, inace false</returns>
public bool BellmanFord(IDirectedGraph <TVertex, TEdge> graph, TVertex start)
{
//Inicijalizujemo kolekcije
Initialize(graph, start);
//Prolazimo kroz sve grane grafa |V|-1 puta i osvezavamo rastojanja izmedju nod-ova.
//U slucaju da nema ciklusa sa kruznim pojacanjem, to ce da garantuje da su sve najkrace
//putanje otkrivene (pogledati teorijsku osnovu algoritma).
for (int i = 0; i < graph.VertexCount - 1; i++)
{
foreach (TEdge edge in graph.Edges)
{
OnExamineVertex(edge.Source);
if (RelaxEdge(edge))
{
OnEdgeRelaxed(edge);
}
}
}
//Provera na negativne cikluse, ako se nakon |V|-1 iteracija javlja novo osvezenje
//grane u grafu, to je potvrda da postoje takvi ciklusi.
foreach (TEdge edge in graph.Edges)
{
if (RelaxEdge(edge))
{
return(true);
}
}
return(false);
}
public StrongComponentChecker(IDirectedGraph <NodeType, EdgeType> graph)
{
this.graph = graph;
dfs = new DepthFirstSearch <NodeType, EdgeType>(graph);
CanCreateNodeData <NodeType> data = (CanCreateNodeData <NodeType>)graph;
DiscoverTime = data.CreateNodeData <int>(0);
RootDiscoverTime = data.CreateNodeData <int>(0);
dfs.DiscoverNode += delegate(NodeType node)
{
DiscoverTime[node] = time;
RootDiscoverTime[node] = time;
time++;
};
dfs.BackEdge += ProcessEdge2;
dfs.CrossEdge += ProcessEdge2;
dfs.FinishTreeEdge += ProcessEdge;
dfs.FinishNode += delegate(NodeType node)
{
int thisRootDiscoverTime = RootDiscoverTime[node];
if (thisRootDiscoverTime < DiscoverTime[node])
{
// not a root
}
else
{
// root of a component
if (thisRootDiscoverTime != 0)
{
IsStrong = false;
}
}
};
}
public BackwardScheduler(Stack <INode> rootNodes, IDirectedGraph <INode> orderOperationGraph,
bool clearOldTimes)
{
_S = rootNodes;
_orderOperationGraph = orderOperationGraph;
_clearOldTimes = clearOldTimes;
}
/// <summary>
/// Dijsktra algoritam za trazenje najmanjeg rastojanja i odgovarajucih
/// putanja. Graf mora imati sve pozitivne tezine grana ali moze da bude neusmeren
/// i/ili da sadrzi cikluse (petlje).
/// </summary>
/// <param name="start"></param>
public void Dijkstra_shortest_path(IDirectedGraph <TVertex, TEdge> graph, TVertex start)
{
//Inicijalizujemo kolekcije
Initialize(graph, start);
minQueue.Clear();
minQueue.Insert(start);
while (minQueue.Count > 0)
{
TVertex u = minQueue.Remove();
if (vertexColors[u] == VertexColor.Black)
{
continue;
}
vertexColors[u] = VertexColor.Black;
OnExamineVertex(u);
foreach (TEdge edge in graph.OutEdges(u))
{
if (RelaxEdge(edge))
{
vertexColors[edge.Target] = VertexColor.Gray;
minQueue.Insert(edge.Target);
OnEdgeRelaxed(edge);
}
}
}
}
private void ScheduleBackwardSecond(IDirectedGraph <INode> orderOperationGraph)
{
INodes childRootNodes = new Nodes();
foreach (var rootNode in orderOperationGraph.GetRootNodes())
{
if (rootNode.GetEntity().GetType() != typeof(CustomerOrderPart))
{
continue;
}
Providers childProviders = ZppConfiguration.CacheManager.GetAggregator()
.GetAllChildProvidersOf((Demand)rootNode.GetEntity());
if (childProviders == null || childProviders.Count() > 1)
{
throw new MrpRunException(
"After Mrp1 a CustomerOrderPart MUST have exact one child.");
}
childRootNodes.AddAll(childProviders.ToNodes());
}
IBackwardsScheduler backwardsScheduler =
new BackwardScheduler(childRootNodes.ToStack(), orderOperationGraph, false);
backwardsScheduler.ScheduleBackward();
}
private static IList <TNode> ReconstructPath(IDirectedGraph <TNode, TEdge> graph, IReadOnlyDictionary <string, string> cameFrom, string currentNodeId)
{
var path = new List <TNode>();
ReconstructPath(graph, cameFrom, currentNodeId, path);
return(path);
}
public void ReplaceNodeByDirectedGraph(Id nodeId, IDirectedGraph <INode> graphToInsert)
{
INodes predecessors = GetPredecessorNodes(nodeId);
INodes successors = GetSuccessorNodes(nodeId);
RemoveNode(nodeId, false);
// predecessors --> roots
if (predecessors != null)
{
foreach (var predecessor in predecessors)
{
foreach (var rootNode in graphToInsert.GetRootNodes())
{
AddEdge(new Edge(predecessor, rootNode));
}
}
}
// leafs --> successors
if (successors != null)
{
foreach (var leaf in graphToInsert.GetLeafNodes())
{
foreach (var successor in successors)
{
AddEdge(new Edge(leaf, successor));
}
}
}
// add all edges from graphToInsert
AddEdges(graphToInsert.GetEdges());
}
private void DFS(IDirectedGraph graph, int vertex)
{
onStack[vertex] = true;
isConnected[vertex] = true;
foreach (int v in graph.Adjacent(vertex))
{
if (HasCycle())
{
return;
}
if (!isConnected[v])
{
edgeTo[v] = vertex;
DFS(graph, v);
}
// 如果当前相邻顶点被标记过，并且在递归调用栈上，说明路径又回到了之前的顶点，也就是出现环路
else if (onStack[v])
{
cycle = new Stack <int>();
// 把路径上的所有顶点记录下来
for (int i = vertex; i != v; i = edgeTo[i])
{
cycle.Push(i);
}
cycle.Push(v);
cycle.Push(vertex);
}
}
onStack[vertex] = false;
}
private void Visit(
IDirectedGraph <TVertex, TEdge> graph,
TVertex vertex,
SearchState <TVertex, TEdge> state,
Queue <TVertex> output)
{
if (state.HasPermanentMark(vertex))
{
return;
}
if (state.HasTemporaryMark(vertex))
{
throw new CyclicGraphsNotSupportedException();
}
state.SetTemporaryMark(vertex);
foreach (var connectedVertex in graph.OutEdges(vertex).Select(e => e.To))
{
this.Visit(graph, connectedVertex, state, output);
}
state.RemoveTemporaryMark(vertex);
state.SetPermanentMark(vertex);
output.Enqueue(vertex);
}
private void solve(IDirectedGraph g)
{
result = new List <int>();
Degrees degrees_info = new Degrees(g);
int[] degrees = new int[g.V];
for (int i = 0; i < g.V; ++i)
{
degrees[i] = degrees_info.InDegree(i);
}
Queue <int> starts = new Queue <int>();
foreach (Int32 s in degrees_info.Sources())
{
starts.Enqueue(s);
}
//只要还有顶点
while (starts.Count > 0)
{
Int32 v = starts.Dequeue();
result.Add(v);
foreach (var w in g.Adj(v))
{
//删除这个顶点的指出的边，因为这个顶点已经被删除了
--degrees[w];
if (degrees[w] == 0)
{
//下一个拓扑排序的顺序
starts.Enqueue(w);
}
}
}
}
public PathFinder(IDirectedGraph <NodeType> graph)
{
this.graph = graph;
CanCreateNodeData <NodeType> data = (CanCreateNodeData <NodeType>)graph;
isBlocked = data.CreateNodeData <bool>(false);
}
public GanttChart(IDirectedGraph <INode> orderOperationGraph)
{
Dictionary <Id, List <Interval> > groups = new Dictionary <Id, List <Interval> >();
foreach (var graphNode in orderOperationGraph.GetNodes())
{
IScheduleNode node = graphNode.GetNode().GetEntity();
if (node.GetType() != typeof(ProductionOrderOperation) && node.GetType() != typeof(PurchaseOrderPart))
{
continue;
}
GanttChartBar ganttChartBar = new GanttChartBar();
ganttChartBar.operation = node.GetId().ToString();
ganttChartBar.operationId = node.GetId().ToString();
ganttChartBar.resource = DetermineFreeGroup(groups,
new Interval(node.GetId(), node.GetStartTimeBackward(), node.GetEndTimeBackward())).ToString();
;
ganttChartBar.start = node.GetStartTimeBackward().GetValue().ToString();
ganttChartBar.end = node.GetEndTimeBackward().GetValue().ToString();
ganttChartBar.groupId = ganttChartBar.resource;
AddGanttChartBar(ganttChartBar);
}
}
public static void buildGraphFromInitialState(IDirectedGraph <char> graph, string rawGraphData)
{
try
{
string[] verticeEdgeData = rawGraphData.Split(",");
foreach (string verticeEdge in verticeEdgeData)
{
string verticeEdgeTrimmed = verticeEdge.Trim();
char vertecie1 = Char.Parse(verticeEdgeTrimmed.Substring(0, 1));
char vertecie2 = Char.Parse(verticeEdgeTrimmed.Substring(1, 1));
float weight = float.Parse(verticeEdgeTrimmed.Substring(2, verticeEdgeTrimmed.Length - 2));
graph.AddVertex(vertecie1);
graph.AddVertex(vertecie2);
graph.AddEdge(vertecie1, vertecie2, weight);
}
}
catch (Exception)
{
Console.WriteLine("The graph data was passed in an incorrect form.\n\tFor a node A that connects to a node B with a weight of 5 pass data in like 'AB5'.\n\tSeparate data by columns: 'AB5, AC2'");
throw;
}
}
private void dfs(IDirectedGraph digraph, int v)
{
onStack[v] = true;
marked[v] = true;
foreach (int w in digraph.Adj(v))
{
if (HasCycle())
{
return;
}
else if (!marked[w])
{
edgeTo[w] = v;
dfs(digraph, w);
}
else if (onStack[w])//如果访问过且在一个路径中
{
cycle = new Stack <int>();
for (int x = v; x != w; x = edgeTo[x])
{
cycle.Push(x);//把前驱放入栈中直到环的起点的后继
}
cycle.Push(w);
cycle.Push(v);//为何从v开始呢？因为v->w是有连接的。此时栈顶和栈底都是一个
}
}
onStack[v] = false;//循环结束，不是一条栈上链的
}
public void TestAsString()
{
INode[] nodes = EntityFactory.CreateDummyNodes(7);
IDirectedGraph <INode> directedGraph = CreateBinaryDirectedGraph(nodes);
Assert.True(directedGraph.ToString() != null,
"AsString() must work in unit tests without a database.");
}
private void ScheduleBackward(Stack <INode> rootNodes,
IDirectedGraph <INode> orderOperationGraph, bool clearOldTimes)
{
IBackwardsScheduler backwardsScheduler =
new BackwardScheduler(rootNodes, orderOperationGraph, clearOldTimes);
backwardsScheduler.ScheduleBackward();
}
public CycleFinder(IDirectedGraph <NodeType> graph)
{
this.graph = graph;
CanCreateNodeData <NodeType> data = (CanCreateNodeData <NodeType>)graph;
isBlocked = data.CreateNodeData <bool>(false);
blockedSources = data.CreateNodeData <Set <NodeType> >(null);
}
public DFSCost(IDirectedGraph graph, int start)
{
this.graph = graph;
this.start = start;
this.visited = new bool[graph.Size];
paths = new Dictionary <int, IEnumerable <int> >();
}
private static void ReconstructPath(IDirectedGraph <TNode, TEdge> graph, IReadOnlyDictionary <string, string> cameFrom, string currentNodeId, ICollection <TNode> thelist)
{
if (cameFrom.ContainsKey(currentNodeId))
{
ReconstructPath(graph, cameFrom, cameFrom[currentNodeId], thelist);
}
thelist.Add(graph[currentNodeId]);
}
public static bool ContainsVertex <T>(this IDirectedGraph <T> graph, T value) where T : IEquatable <T>
{
if (graph is null)
{
throw new ArgumentNullException(nameof(graph));
}
return(graph[value] != default);
}
public DepthFirstSearchGraphEnumerator(IDirectedGraph <TVertex> graph, TVertex origin)
{
Graph = graph;
Origin = origin;
Stack = new Stack <TVertex>();
Visited = new HashSet <TVertex>();
Initialize();
}
/// <inheritdoc />
public IEnumerable <TVertex> Execute(IDirectedGraph <TVertex, TEdge> graph, TVertex startVertex)
{
var output = new Queue <TVertex>(graph.VertexCount);
var state = SearchState.Create(graph);
this.Visit(graph, startVertex, state, output);
return(output);
}
public BreadthFirstSearchGraphEnumerator(IDirectedGraph <TVertex> graph, TVertex origin)
{
Graph = graph;
Origin = origin;
Queue = new Queue <TVertex>();
Visited = new HashSet <TVertex>();
Initialize();
}
protected void Initialize(IDirectedGraph <TVertex, TEdge> graph)
{
this.graph = graph;
vertexColors.Clear();
foreach (TVertex u in graph.Vertices)
{
vertexColors.Add(u, VertexColor.White);
}
}
public IList <TNode> ShortestPath(IDirectedGraph <TNode, TEdge> graph, TNode source, TNode goal)
{
if (source == null || goal == null)
{
return(null);
}
var visited = new HashSet <string>();
var queue = new KeyValueHeap <string, int>(_comparer);
var cameFrom = new Dictionary <string, string>();
var gScore = new Dictionary <string, int>();
var fScore = new Dictionary <string, int>();
queue.Insert(source.Id, 0);
gScore[source.Id] = 0;
fScore[source.Id] = gScore[source.Id] + Heuristic.Evaluate(source, goal);
while (!queue.Empty)
{
var current = graph[queue.RemoveRootKey()];
if (current.Id == goal.Id)
{
return(ReconstructPath(graph, cameFrom, current.Id));
}
visited.Add(current.Id);
foreach (var neighbor in graph.Outgoing(current).Where(neighbor => !visited.Contains(neighbor.Id)))
{
var score = gScore[current.Id] + graph[current, neighbor].Weight;
if (!queue.ContainsKey(neighbor.Id) || score < gScore[neighbor.Id])
{
cameFrom[neighbor.Id] = current.Id;
gScore[neighbor.Id] = score;
var tmpFScore = score + Heuristic.Evaluate(neighbor, goal);
if (queue.ContainsKey(neighbor.Id))
{
if (tmpFScore < fScore [neighbor.Id])
{
fScore[neighbor.Id] = tmpFScore;
queue.SetValue(neighbor.Id, tmpFScore);
}
}
else
{
fScore[neighbor.Id] = tmpFScore;
queue.Insert(neighbor.Id, fScore[neighbor.Id]);
}
}
}
}
return(null);
}
public static bool SetBidirectionalEdge <T>(this IDirectedGraph <T> graph, Vertex <T> firstVertex, Vertex <T> secondVertex, int weight) where T : IEquatable <T>
{
if (graph is null)
{
throw new ArgumentNullException(nameof(graph));
}
return(graph.SetEdge(firstVertex, secondVertex, weight) &&
graph.SetEdge(secondVertex, firstVertex, weight));
}
/// <summary>
/// Adds sequence of vertices to the graph.
/// </summary>
/// <typeparam name="V"></typeparam>
/// <typeparam name="E"></typeparam>
/// <param name="graph"></param>
/// <param name="vertices"></param>
public static void AddVertices <V, E>(this IDirectedGraph <V, E> graph, IEnumerable <V> vertices)
{
using (Trace.Entering())
{
foreach (V vertex in vertices)
{
graph.AddVertex(vertex);
}
}
}
public void TestRemoveNode()
{
INode[] nodes = EntityFactory.CreateDummyNodes(6);
IDirectedGraph <INode> directedGraph = CreateBinaryDirectedGraph(nodes);
INode nodeToRemove = nodes[2];
directedGraph.RemoveNode(nodeToRemove, false);
Assert.True(directedGraph.Contains(nodeToRemove) == false);
}
public TopologicalSort(IDirectedGraph g) : base(g)
{
digraph = g;
}
public StronglyConnectedComponents(IDirectedGraph g) {
graph = g;
dfs = new DepthFirstSearch(g);
dfs.VisitingVertex += Dfs_VisitingVertex;
}