private char selectNextDirection(Point[] players, int myPlayerIndex, bool debugMode)
{
// 2
// .
// 0.....1
// . .
// . .
//start timer
var me = players[myPlayerIndex];
var opponents = players.Except(new[] { me }).ToArray();
if (debugMode) Player.Debug("I'm at {0}", Point.From(me.Index, map.Width, map.Height));
MaxiMinState bestPath = null;
var queue = new Queue<MaxiMinState>();
var nodes = nodesFrom(map);
// push all my exits to queue bundled with opponents current positions
queue.Enqueue(new MaxiMinState { Steps = new[] { me.Index }, Me = me.Index, Opponents = opponents.Select(x => x.Index).ToArray(), Score = 0 });
var counter = 0;
// foreach position in queue
while (queue.Any() && timer.ElapsedMilliseconds < MAX_AI_TIME_MS)
{
// position me at new position
counter++;
var state = queue.Dequeue();
var myPath = string.Join("-", state.Steps);
// push all new exits to queue (with path) bundled with opponents new positions
foreach (var exit in nodes[state.Me].Neighbours.ToArray())//.Where(x => x.Cost == 1.0)
{
if (timer.ElapsedMilliseconds >= MAX_AI_TIME_MS)
{
Console.Error.WriteLine("Looping through exits when time is up.");
break; //Time is up
}
//if (debugMode) Console.Error.Write("{0}: Eval {1}->{2} [{3}]: ", counter, myPath, exit.Node.Id, string.Join(", ", state.Opponents));
if (state.Opponents.Any(x => x == exit.Node.Id))
{
//if (debugMode) Console.Error.WriteLine("Walked into opponent");
continue;
}
// move opponents towards my new position
var opponentNewPositions = new int[state.Opponents.Length];
for (int i = 0; i < state.Opponents.Length; i++)
{
if (timer.ElapsedMilliseconds >= MAX_AI_TIME_MS)
{
Console.Error.WriteLine("Looping through opponents when time is up.");
break; //Time is up
}
var opponentPath = new Dijkstra(nodes, state.Opponents[i]);
var newPosition = opponentPath.GetPathTo(exit.Node.Id).Skip(1).First();
if (newPosition == exit.Node.Id)
{
//if (debugMode) Console.Error.WriteLine("Killed by opponent");
break;
}
opponentNewPositions[i] = newPosition;
}
if (opponentNewPositions.Last() == 0)
continue; //We were killed by opponent in inner loop or time is up
var score = state.Score + valueOf(map[exit.Node.Id]);
var newState = new MaxiMinState { Steps = state.Steps.Concat(new[] { exit.Node.Id }).ToArray(), Me = exit.Node.Id, Opponents = opponentNewPositions, Score = score };
if (bestPath == null || bestPath.Score < newState.Score)
{
bestPath = newState;
if (debugMode) Console.Error.Write("{0}: Eval {1}->{2} [{3}]: ", counter, myPath, exit.Node.Id, string.Join(", ", state.Opponents));
if (debugMode) Console.Error.WriteLine("Score {0}", newState.Score);
}
//else
//{
// if (debugMode) Console.Error.WriteLine("----- {0}", newState.Score);
//}
queue.Enqueue(newState);
}
// if queue empty or time is up, break
}
//walk towards the best path
Player.Debug("Calculated {0} iterations. Best path is {1} steps.", counter, bestPath == null ? 0 : bestPath.Steps.Length);
var nextTile = bestPath == null || bestPath.Steps.Length < 2 ? me.Index : bestPath.Steps.Skip(1).First();
//if (debugMode) Player.Debug("Moving to {0} through {1}", bestPath == null ? nextTile : bestPath.Me, nextTile);
return map.DirectionTo(me, nextTile);
}