private static bool HamiltonCycleUtil(EulerGraph graph, int[] cycle, int position)
{
if (position == cycle.Length)
{
if (graph.IsEdgeExists(cycle[0], cycle[position - 1]))
{
return(true);
}
else
{
return(false);
}
}
for (int i = 1; i < graph._numberOfVertices; i++)
{
if (IsSafe(i, position, cycle, graph))
{
cycle[position] = i;
if (HamiltonCycleUtil(graph, cycle, position + 1))
{
return(true);
}
cycle[position] = -1;
}
}
return(false);
}
private static int HamiltonAllCycles(EulerGraph graph, int[] cycle, int position, ref int numberOfCycles, bool print = false)
{
if (position == cycle.Length)
{
if (graph.IsEdgeExists(cycle[0], cycle[position - 1]))
{
return(1);
}
}
for (int i = 1; i < graph._numberOfVertices; i++)
{
if (IsSafe(i, position, cycle, graph))
{
cycle[position] = i;
if (HamiltonAllCycles(graph, cycle, position + 1, ref numberOfCycles, print) == 1)
{
numberOfCycles++;
if (print)
{
Console.Write(numberOfCycles + ": ");
foreach (var item in cycle)
{
Console.Write(item + " ");
}
Console.WriteLine();
}
}
cycle[position] = -1;
}
}
return(0);
}
private static bool IsSafe(int v, int position, int[] cycle, EulerGraph graph)
{
if (!graph.IsEdgeExists(v, cycle[position - 1]))
{
return(false);
}
foreach (var vertex in cycle)
{
if (vertex == v)
{
return(false);
}
}
return(true);
}