static void Main(string[] args)
{
//string[] dataFiles = new string[]
//{@"tinyEWG.txt",
// @"mediumEWG.txt"
//};
//foreach (var file in dataFiles)
//{
// var input = File.ReadAllLines(file);
// EdgeWeightedGraph ewg = new EdgeWeightedGraph(input);
// LazyPrimMST mst = new LazyPrimMST(ewg);
// foreach (var e in mst.Edges())
// {
// Console.WriteLine(e);
// }
// Console.WriteLine(mst.Weight());
//}
var file = @"tinyEWD.txt";
var data = File.ReadAllLines(file);
var ewd = new EdgeWeightedDiGraph(data);
DijkstrasShortestPath dsp = new DijkstrasShortestPath(ewd, 0);
var sp = dsp.PathTo(5);
foreach (var p in sp)
{
Console.WriteLine(p);
}
}
//ctor inits DSs, builds shortest path tree and computes distances
//takes a built DiGraph and a source vertex
public DijkstrasShortestPath(EdgeWeightedDiGraph g, int s)
{
_pq = new IndexMinPQ <double>(g.V);
_edgeTo = new DirectedEdge[g.V];
_distTo = new double[g.V];
//load initial values
for (int i = 1; i < g.V; i++)
{
_distTo[i] = Double.PositiveInfinity;
}
_distTo[s] = 0.0;
_edgeTo[s] = null;
//loads a starting value onto PQ to start process
_pq.Insert(s, _distTo[s]);
//start business logic
//start cycle of deleting min edges and checking adj edges for 'eligability'
while (!_pq.IsEmpty())
{
var minV = _pq.DelMin();
Relax(g, minV);
}
}
private void Relax(EdgeWeightedDiGraph g, int v)
{
foreach (var edge in g.Adj(v))
{
//test if current weight of path to W is more than going through v; ie v 'relaxes' the path
int w = edge.To();
double distViaV = _distTo[v] + edge.Weight();
//if current distTo w is greater than (distTo v + this.edge weight), then add/or replace on arrays and PQ
if (distViaV < _distTo[w])
{
_distTo[w] = distViaV;
_edgeTo[w] = edge;
if (_pq.Contains(w))
{
_pq.Change(w, distViaV);
}
else
{
_pq.Insert(w, distViaV);
}
}
}
}
static int minimumMovesDij(string[] grid, int startX, int startY, int goalX, int goalY)
{
int from = -1;
int to = -1;
int n = grid.Length;
int[][] matrix = new int[n][];
int tracker = 0;
for (int i = 0; i < n; i++)
{
matrix[i] = new int[n];
for (int j = 0; j < n; j++)
{
if (grid[i][j] != 'X')
{
matrix[i][j] = tracker;
}
else
{
matrix[i][j] = -1;
}
tracker++;
if (startX == i && startY == j)
{
from = matrix[i][j];
}
if (goalX == i && goalY == j)
{
to = matrix[i][j];
}
}
}
EdgeWeightedDiGraph ewdg = new EdgeWeightedDiGraph(tracker);
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
if (i < n - 1 && matrix[i][j] != -1 && matrix[i + 1][j] != -1)
{
ewdg.AddEdge(new DirectedEdgeAPI(matrix[i][j], matrix[i + 1][j], 1), "V");
ewdg.AddEdge(new DirectedEdgeAPI(matrix[i + 1][j], matrix[i][j], 1), "V");
}
if (j < n - 1 && matrix[i][j] != -1 && matrix[i][j + 1] != -1)
{
ewdg.AddEdge(new DirectedEdgeAPI(matrix[i][j], matrix[i][j + 1], 1), "H");
ewdg.AddEdge(new DirectedEdgeAPI(matrix[i][j + 1], matrix[i][j], 1), "H");
}
}
}
BellmanFordShortestPath djkForward = new BellmanFordShortestPath(ewdg, from);
//DijkstraShortestPath djkBackward = new DijkstraShortestPath(ewdg, from);
//var count = djkForward.DistTo[to] > djkBackward.DistTo[from] ? djkBackward.DistTo[from] : djkForward.DistTo[to];
//List<int> list = djk.PathTo(from, to).ToList();
//string previousAllign = string.Empty;
//int count = 0;
//for (int i = 0; i < list.Count() - 1; i++)
//{
// string key = list[i] < list[i + 1] ? list[i] + "|" + list[i + 1] : list[i + 1] + "|" + list[i];
// var item = ewdg.dict[key];
// if (previousAllign == string.Empty || previousAllign != item)
// {
// count++;
// previousAllign = item;
// }
//}
return((int)0);
}
