public RandomWalkAi(
IStartPathStrategy startPathStrategy,
IPathEstimator estimator,
bool useAllowedDirections,
bool useTerritoryTtl,
bool killWithMinimax)
{
this.startPathStrategy = startPathStrategy;
this.estimator = estimator;
this.useAllowedDirections = useAllowedDirections;
randomPath = new RandomPathGenerator();
reliablePathBuilder = new ReliablePathBuilder(useTerritoryTtl);
allowedDirectionsFinder = new AllowedDirectionsFinder(4, killWithMinimax);
}
public RequestOutput GetCommand(State state, int player, ITimeManager timeManager, Random random)
{
if (commands == null)
{
commands = new Direction[state.players.Length];
}
randomPath.random = random;
distanceMap.Build(state);
facts.Build(state, distanceMap);
if (TryKillOpponent(state, player, out var kill))
{
return(kill);
}
backup.Backup(state);
estimator.Before(state, player);
var allowedDirectionsMask = useAllowedDirections
? allowedDirectionsFinder.GetAllowedDirectionsMask(timeManager.GetNested(70), state, player, distanceMap, facts)
: (byte)0xFF;
if (allowedDirectionsMask != 0 && (allowedDirectionsMask & (allowedDirectionsMask - 1)) == 0)
{
for (int d = 0; d < 4; d++)
{
if ((allowedDirectionsMask & (1 << d)) != 0)
{
return new RequestOutput {
Command = (Direction)d, Debug = $"Only one allowed direction. AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
}
}
;
}
}
if (allowedDirectionsFinder.killWithMinimax)
{
var bestKillScore = 0.0;
Direction?bestKillCommand = null;
for (int d = 0; d < 4; d++)
{
if ((allowedDirectionsMask & (1 << d)) != 0 && allowedDirectionsFinder.minimax.bestResultScores[d] > bestKillScore)
{
bestKillScore = allowedDirectionsFinder.minimax.bestResultScores[d];
bestKillCommand = (Direction)d;
}
}
if (bestKillScore > AllowedDirectionsFinder.killScore)
{
return new RequestOutput {
Command = bestKillCommand, Debug = $"Gotcha with minimax! AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
}
}
;
}
var pathCounter = 0;
var validPathCounter = 0;
Direction?bestDir = null;
double bestScore = 0;
var bestLen = 0;
string bestPath = null;
long simulations = 0;
long bestPathCounter = 0;
var opponentCapturedFound = false;
while (allowedDirectionsMask != 0 && !timeManager.IsExpired)
{
++pathCounter;
if (randomPath.Generate(state, player, distanceMap, facts, reliablePathBuilder, allowedDirectionsMask))
{
++validPathCounter;
var dir = default(Direction);
for (var i = 0; i < state.players.Length; i++)
{
if (i != player)
{
facts.pathsToOwned[i].Reset();
}
else
{
facts.pathsToOwned[i].BuildPath(state, reliablePathBuilder, i);
dir = facts.pathsToOwned[i].CurrentAction();
}
}
while (true)
{
for (var i = 0; i < state.players.Length; i++)
{
if (state.players[i].status == PlayerStatus.Eliminated || state.players[i].status == PlayerStatus.Broken)
{
continue;
}
if (state.players[i].arriveTime != 0)
{
continue;
}
commands[i] = facts.pathsToOwned[i].ApplyNext(state, i);
}
state.NextTurn(commands, false);
simulations++;
if (state.isGameOver || state.players[player].status == PlayerStatus.Eliminated || facts.pathsToOwned[player].len == 0 && state.players[player].arriveTime == 0)
{
if (state.players[player].status != PlayerStatus.Eliminated)
{
if (!opponentCapturedFound && state.players[player].opponentTerritoryCaptured > 0)
{
opponentCapturedFound = true;
}
if (!opponentCapturedFound || state.players[player].opponentTerritoryCaptured > 0)
{
var score = estimator.Estimate(state, facts, player, reliablePathBuilder.startLen);
if (score > bestScore || score > bestScore - 1e-6 && reliablePathBuilder.len < bestLen)
{
bestScore = score;
bestDir = dir;
bestLen = reliablePathBuilder.len;
bestPath = facts.pathsToOwned[player].Print();
bestPathCounter = pathCounter;
Logger.Debug($"Score: {bestScore}; Path: {bestPath}");
if (Logger.IsEnabled(Logger.Level.Debug))
{
for (var i = 0; i < state.players.Length; i++)
{
Logger.Debug($"{i}: {facts.pathsToOwned[i].Print()} {state.players[i].status}");
}
}
}
}
}
break;
}
}
backup.Restore(state);
}
}
if (bestDir == null)
{
if (TryGotoStart(state, player, allowedDirectionsMask, out var gotoStart))
{
return(gotoStart);
}
facts.pathsToOwned[player].BuildPath(state, distanceMap, player, distanceMap.nearestOwned[player]);
if (facts.pathsToOwned[player].len > 0)
{
var returnAction = facts.pathsToOwned[player].CurrentAction();
if ((allowedDirectionsMask & (1 << (int)returnAction)) != 0 || allowedDirectionsMask == 0)
{
return new RequestOutput {
Command = returnAction, Debug = $"No path found. Returning back to territory. Paths: {pathCounter}. ValidPaths: {validPathCounter}. Simulations: {simulations}. AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
}
}
;
}
Direction?validDir = null;
if (state.players[player].dir == null)
{
for (var d = 0; d < 4; d++)
{
if ((allowedDirectionsMask & (1 << d)) != 0)
{
var next = state.players[player].arrivePos.NextCoord((Direction)d);
if (next != ushort.MaxValue)
{
validDir = (Direction)d;
if (state.territory[next] == player)
{
return new RequestOutput {
Command = (Direction)d, Debug = $"No path found. Walking around (null). Paths: {pathCounter}. ValidPaths: {validPathCounter}. Simulations: {simulations}. AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
}
}
;
}
}
}
}
else
{
var sd = random.Next(3);
for (var d = 0; d < 4; d++)
{
var nd = (Direction)(((int)state.players[player].dir.Value + 3 + sd + d) % 4);
if (nd == (Direction)(((int)state.players[player].dir.Value + 2) % 4))
{
continue;
}
if ((allowedDirectionsMask & (1 << (int)nd)) != 0)
{
var next = state.players[player].arrivePos.NextCoord(nd);
if (next != ushort.MaxValue)
{
validDir = nd;
if (state.territory[next] == player)
{
return new RequestOutput {
Command = nd, Debug = $"No path found. Walking around. Paths: {pathCounter}. ValidPaths: {validPathCounter}. Simulations: {simulations}. AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
}
}
;
}
}
}
}
return(new RequestOutput {
Command = validDir ?? throw new InvalidOperationException("validDir is null"), Debug = $"No path found. Walking around (not self). Paths: {pathCounter}. ValidPaths: {validPathCounter}. Simulations: {simulations}. AllowedDirections: {AllowedDirectionsFinder.DescribeAllowedDirectionsMask(allowedDirectionsMask)} (depth {allowedDirectionsFinder.minimax.bestDepth})"
});
