private int _getShortestPath(int[][] arr, int[][] distances, MatrixPoint start, MatrixPoint end, int curDistance)
{
// if out of bounds, return
if (start.R < 0 || start.R >= arr.Length || start.C < 0 || start.C >= arr.Length)
{
return(int.MaxValue);
}
// if already visited, return
if (distances[start.R][start.C] != int.MaxValue)
{
return(int.MaxValue);
}
// set distance to the shortest distance to this block
distances[start.R][start.C] = Math.Min(distances[start.R][start.C], curDistance);
var queue = new Queue <MatrixPoint>();
queue.Enqueue(start); // enqueue first point
//while (queue.Count != 0)
//{
//}
// breadth first to fill out entire distances matrix
_getShortestPath(arr, distances, new MatrixPoint(start.R + 1, start.C), end, curDistance + 1);
_getShortestPath(arr, distances, new MatrixPoint(start.R - 1, start.C), end, curDistance + 1);
_getShortestPath(arr, distances, new MatrixPoint(start.R, start.C + 1), end, curDistance + 1);
_getShortestPath(arr, distances, new MatrixPoint(start.R, start.C - 1), end, curDistance + 1);
return(distances[end.R][end.C]);
}
public int GetShortestPath(int[][] arr, MatrixPoint start, MatrixPoint end)
{
var distances = GetDistancesArray(arr);
return(_getShortestPath(arr, distances, start, end, 0));
}
