} // TSP_TreeBased
public static int?buildCycle(Graph g, out Edge[] cycle)
{
cycle = null;
int[] verticesOrder = new int[g.VerticesCount];
int orderCounter = 0;
Graph tree;
g.Kruskal(out tree);
Predicate <int> preVisit = delegate(int i)
{
verticesOrder[orderCounter++] = i;
return(true);
};
tree.DFSearchFrom(0, preVisit, null);
cycle = new Edge[g.VerticesCount];
int sum = 0;
int weight;
for (int i = 0; i < g.VerticesCount - 1; i++)
{
if (!g.GetEdgeWeight(verticesOrder[i], verticesOrder[i + 1]).HasValue)
{
cycle = null;
return(null);
}
weight = g.GetEdgeWeight(verticesOrder[i], verticesOrder[i + 1]).Value;
sum += weight;
cycle[i] = new Edge(verticesOrder[i], verticesOrder[i + 1], weight);
}
weight = g.GetEdgeWeight(verticesOrder[tree.VerticesCount - 1], verticesOrder[0]).Value;
sum += weight;
cycle[tree.VerticesCount - 1] = new Edge(verticesOrder[tree.VerticesCount - 1], verticesOrder[0], weight);
return(sum);
}