public TreasureC()
{
Console.ReadLine();
var mapString = "";
var next = Console.ReadLine();
while (next != null)
{
mapString += next + "\n";
next = Console.ReadLine();
}
//var mapString = File.ReadAllText("map.txt");
var rows = mapString.Split('\n');
var n = rows.Length-1;
var map = new List<char[]>();
for (var i = 0; i < n; i++)
map.Add(rows[i].ToCharArray());
Pos entry = null;
for (var y = 0; y < n; ++y)
for (int x = 0; x < n; ++x)
if (map[y][x] == 'I') entry = new Pos(x, y);
if (entry == null) return;
var frontier = new Queue<Pos>();
frontier.Enqueue(entry);
Pos last = null;
while (frontier.Count > 0)
{
var curr = frontier.Dequeue();
map[curr.Y][curr.X] = '#';
if (ProcessTile(n, curr.X-1, curr.Y, frontier, map, curr, "W", ref last)
|| ProcessTile(n, curr.X+1, curr.Y, frontier, map, curr, "E", ref last)
|| ProcessTile(n, curr.X, curr.Y+1, frontier, map, curr, "S", ref last)
|| ProcessTile(n, curr.X, curr.Y-1, frontier, map, curr, "N", ref last))
break;
}
// trace the path, if any
var route = new StringBuilder();
var t = last;
while (t != null)
{
route.Append(t.Dir + " ");
t = t.Parent;
}
var s = route.ToString();
char[] charArray = s.ToCharArray();
Array.Reverse( charArray );
var rt = new string( charArray );
Console.WriteLine(rt);
}
private bool ProcessTile(int n, int px, int py, Queue<Pos> frontier, List<char[]> map, Pos current, string direction, ref Pos last)
{
if (IsValidPos(n, py, px) && map[py][px] != '#')
{
var p = new Pos(px, py, current, direction);
// have we found the treasure?
if (map[py][px] == '$')
{
last = p;
return true;
}
frontier.Enqueue(p);
map[py][px] = '#';
}
return false;
}
public Pos(int x, int y, Pos parent, string dir)
{
this.X = x;
this.Y = y;
this.Parent = parent;
this.Dir = dir;
}