static void Main()
{
theNode[] nodes = new theNode[5];
for (int i = 0; i < 5; i++)
{
nodes[i] = new theNode();
nodes[i].name = i;
}
nodes[0].adjacentNodes.Add(nodes[0]);
nodes[0].adjacentNodes.Add(nodes[1]);
nodes[0].adjacentNodes.Add(nodes[3]);
nodes[1].adjacentNodes.Add(nodes[1]);
nodes[1].adjacentNodes.Add(nodes[2]);
nodes[2].adjacentNodes.Add(nodes[2]);
nodes[2].adjacentNodes.Add(nodes[4]);
nodes[3].adjacentNodes.Add(nodes[3]);
nodes[3].adjacentNodes.Add(nodes[1]);
nodes[3].adjacentNodes.Add(nodes[4]);
nodes[4].adjacentNodes.Add(nodes[4]);
theNode s = nodes[0]; //Setting the start
theNode d = nodes[4]; //setting the destination
BreadthFirst(nodes, s, d);
}
static void BreadthFirst(theNode[] nodes, theNode s, theNode d)
{
Queue <theNode> q = new Queue <theNode>();
s.distanceFromS = 0;
q.Enqueue(s);
for (int currDist = 0; currDist < nodes.Length; currDist++) //the immediate distance we are checking in the breadth-first search
{
while (q.Count > 0 && q.Peek().distanceFromS == currDist) //ensures that we stop the dequeue once we are considering nodes further away than the current distance we are considering
{
theNode i = q.Dequeue();
if (i.known == false && i.distanceFromS == currDist)
{
i.known = true;
foreach (theNode j in i.adjacentNodes)
{
if (j.distanceFromS == -1)
{
j.distanceFromS = currDist + 1;//here we gaurantee we will check this node in the next pass
j.path = i.name;
q.Enqueue(j);
}
}
}
}
}
Console.WriteLine("The distance to d is" + " " + d.distanceFromS);
Console.WriteLine("The path starts at node" + " " + s.name);
Stack <theNode> tempStack = new Stack <theNode>();//Here we simulate recursion with a stack
theNode check = d;
int p = 0;
int pathLength = d.distanceFromS;
while (p < pathLength)
{
tempStack.Push(check);
check = nodes[check.path];
p++;
}
while (tempStack.Count > 0)
{
Console.WriteLine("Followed by node" + " " + tempStack.Pop().name);
}
}