BellmanFordSP::BellmanFordSP(const EWDiGraph& graph, int source) : distances(graph.getVertexCount(), std::numeric_limits<double>::max()),
edges(graph.getVertexCount(), Edge(0, 0, 0.0))
{
std::queue<int> considerVertecies;
for (int i = 0; i < graph.getVertexCount(); i++)
{
considerVertecies.push(i);
}
distances[source] = 0.0;
for (int i = 0; i < graph.getVertexCount(); i++)
{
std::queue<int> nextPassVertecies;
while (!considerVertecies.empty())
{
if (i == graph.getVertexCount() - 1)
findNegativeCycle(considerVertecies.front());
EWDiGraph::EdgesList adjacent = graph.getAdjacentVertex(considerVertecies.front());
for (auto k = adjacent.begin(); k != adjacent.end(); ++k)
{
relax(*k, nextPassVertecies);
}
considerVertecies.pop();
}
considerVertecies = nextPassVertecies;
}
}
void BellmanFord::relax(EdgeWeightedDigraph &G, int v){
std::deque<DirectedEdge>::const_iterator it;
for(it = G.Iterable(v)->begin(); it != G.Iterable(v)->end(); ++it){
int w = it->to();
if(distTo[w] > distTo[v] + it->Getweight()){
distTo[w] = distTo[v] + it->Getweight();
edgeTo[w] = *it;
if(!onQ[w])
{
queue.push_back(w);
onQ[w]=true;
}
}
if(cost++ % G.GetV() == 0)
findNegativeCycle();
}
}
