static void Dijkstra(List <Node> nodelist, Node root)
{
//set all distances from root
List <Node> Nodelist = new List <Node>();
foreach (Node node in nodelist)
{
Nodelist.Add(node);
if (!root.Distances.ContainsKey(node))
{
root.Distances[node] = int.MaxValue;
node.bestpath[root] = null;
}
}
root.Distances[root] = 0; //forces first selectednode to be the root
while (Nodelist.Count > 0)
{
Node selectednode = root;
selectednode = selectednode.MinDistanceToNode(Nodelist); // selects node with minimal costs (I am not using queue because you don't know all the costs so you don't know the order)
Console.WriteLine(selectednode.Letter); // prints node so you can see the path it takes
Nodelist.Remove(selectednode); // removes the selected node from lists
foreach (Node neighbour in selectednode.Adjacentnodes)
{
// Normally you would calculate the costs between neighbour nodes here. But I calculated those beforehand
int alt = root.Distances[selectednode] + selectednode.Distances[neighbour];
//for not going negative if value gets over int cap
if (root.Distances[selectednode] == int.MaxValue || selectednode.Distances[neighbour] == int.MaxValue)
{
alt = int.MaxValue;
}
// replaces distance if found a shorter path
else if (alt < root.Distances[neighbour])
{
root.Distances[neighbour] = alt;
root.bestpath[neighbour] = selectednode;
}
}
}
}
