public static IDictionary <char, int> scan_reachable(WorldSlow world, Point start, string allowed)
{
//var res = {};
var res = new Dictionary <char, int>();
var seen = new HashSet <Point>();
var pending = new Queue <Point>();
pending.Enqueue(start);
seen.Add(start);
while (pending.Count != 0)
{
var point = pending.Dequeue();
for (var i = 0; i < 4; i++)
{
var neighbor = point.step((Dir)i);
if (seen.Contains(neighbor))
{
continue;
}
seen.Add(neighbor);
var cell = world.get(neighbor);
var c = cell != null?cell.get_char() : ' ';
if (c == '-' || c == '\\' || c == '|')
{
c = '/';
}
if (res.ContainsKey(c))// (res[c])
{
res[c]++;
}
else
{
res[c] = 1;
}
if (allowed.Contains(c))
{
pending.Enqueue(neighbor);
}
}
}
return(res);
}
