public static Ant CreateSolutionNN(Graph graph, UInt32 startNode = 0)
{
Ant ant = new Ant();
ant.Initialize(graph.dimension);
UInt32 currentNode = startNode;
ant.Visit(currentNode);
for (int i = 1; i < graph.dimension; i++)
{
UInt32 nextNode = NextNode(graph, (UInt32)i, ant);
if (nextNode == currentNode)
{
double minDistance = double.MaxValue;
for (UInt32 node = 0; node < graph.dimension; ++node)
{
if (!ant.IsVisited(node))
{
var distance = graph.edgeWeight[currentNode, node];
if (distance < minDistance)
{
minDistance = distance;
nextNode = node;
}
}
}
}
ant.Visit(nextNode);
currentNode = nextNode;
}
return(ant);
}
public static UInt32[] SortNodes(Graph graph, UInt32 actualNode, Ant ant)
{
//UInt32[] nodes = new UInt32[graph.dimension - (UInt32)ant.visited.Count];
List <double> weights = new List <double>();
for (UInt32 i = 0; i < graph.edgeWeight.Length; i++)
{
if (i == actualNode)
{
continue;
}
if (ant.IsVisited(i))
{
continue;
}
weights.Add(graph.edgeWeight[actualNode, i]);
}
weights.Sort();
UInt32 [] sortedNodes = new UInt32[weights.Count];
for (UInt32 j = 0; j < weights.Count; j++)
{
for (UInt32 k = 0; k < (UInt32)graph.dimension; k++)
{
if (weights[(int)j] == graph.edgeWeight[actualNode, (int)k])
{
sortedNodes[j] = k;
}
}
}
return(sortedNodes);
}
public static UInt32 MoveAntMMAS(Graph graph, PheromoneMemory pheromone, double[] heuristic, Ant ant)
{
var dimension = graph.dimension;
var currentNode = ant.visited[ant.visited.Count - 1];
UInt32 offset = currentNode * dimension;
UInt32[] candList = new UInt32[MaxCandListSize];
UInt32 candListSize = 0;
for (int i = 0; i < graph.dimension; i++)
{
if (!ant.IsVisited((UInt32)i))
{
candList[candListSize] = (UInt32)i;
++candListSize;
}
}
//candList = SortNodes(graph, currentNode, ant);
UInt32 chosenNode = currentNode;
if (candListSize > 0)
{
double[] productsPrefixSum = new double[MaxCandListSize];
double total = 0;
for (UInt32 j = 0; j < candListSize; ++j)
{
var node = candList[j];
var product = pheromone.Get(currentNode, node) * heuristic[offset + node];
total += product;
productsPrefixSum[j] = total;
}
chosenNode = candList[candListSize - 1];
var r = GetRandomDouble() * total;
for (UInt32 i = 0; i < candListSize; ++i)
{
if (r < productsPrefixSum[i])
{
chosenNode = candList[i];
break;
}
}
}
else
{
double maxProduct = 0;
for (UInt32 node = 0; node < dimension; ++node)
{
if (!ant.IsVisited(node))
{
var product = pheromone.Get(currentNode, node) * heuristic[offset + node];
if (product > maxProduct)
{
maxProduct = product;
chosenNode = node;
}
}
}
}
ant.Visit(chosenNode);
return(chosenNode);
}