public static List<int> DijkstraAlgorithm(Dictionary<Node, Dictionary<Node, int>> graph, Dictionary<int, Node> nodes, int sourceNode, int destinationNode)
{
int[] previous = new int[graph.Count];
bool[] visited = new bool[graph.Count];
PriorityQueue<Node> priorityQueue = new PriorityQueue<Node>();
var startNode = nodes[sourceNode];
startNode.DistanceFromStart = 0;
for (int i = 0; i < previous.Length; i++)
{
previous[i] = -1;
}
priorityQueue.Enqueue(startNode);
while (priorityQueue.Count > 0)
{
var currentNode = priorityQueue.ExtractMax();
if (currentNode.Index == destinationNode)
{
break;
}
foreach (var edge in graph[currentNode])
{
if (!visited[edge.Key.Index])
{
priorityQueue.Enqueue(edge.Key);
visited[edge.Key.Index] = true;
}
var distance = currentNode.DistanceFromStart + edge.Value;
if (distance > edge.Key.DistanceFromStart)
{
edge.Key.DistanceFromStart = distance;
previous[edge.Key.Index] = currentNode.Index;
priorityQueue.DecreaseKey(edge.Key);
}
}
}
if (previous[destinationNode] == -1)
{
return null;
}
List<int> path = new List<int>();
int current = destinationNode;
while (current != -1)
{
path.Add(current);
current = previous[current];
}
path.Reverse();
return path;
}
