public float Score(CachedMultiMetricState state, int index)
{
var me = state.World.Snakes[index];
float score = 0.0f;
if (!state.World.Snakes[BountySnake].Alive && index != BountySnake)
{
// Be really pessimistic everybody hates us
score += 2000.0f;
}
// Try to win as early as possible and lose or draw as late as possible
// Also try to prefer death reasons which are not completely deterministic
if (!me.Alive)
{
return(score - 1000.0f + state.World.Turn / 100.0f - BaseDuellingHeuristic.ScoreKillReason(me.Status));
}
else if (IsTerminal(state))
{
// High score if we are the sole survivor, try to win earlier
return(score + 1000.0f - state.World.Turn / 100.0f);
}
// Else evaluate detailed heuristic if no terminal
return(ScoreDetail(state, index));
}
public float ScoreCached(CachedMultiMetricState state, int ownIndex)
{
var self = state.World.Snakes[ownIndex];
bool ownTailReachable = state.AdversarialFill.Tiles[self.Tail.Y, self.Tail.X].Snake == ownIndex;
if (!ownTailReachable)
{
bool sufficientSpace = state.AdversarialFill.EmptyCounts[ownIndex] > self.MaxLength;
return(sufficientSpace ? 1.0f : -1.0f);
}
else
{
return(1.0f);
}
}
public float Score(CachedMultiMetricState s, int index)
{
if (s.World.Snakes[index].Health > SatisfactionThreshold)
{
return(1.0f);
}
int bestOwnDistance = int.MaxValue;
foreach (var fruit in s.World.Fruits)
{
ref var tile = ref s.AdversarialFill.Tiles[fruit.Y, fruit.X];
if (tile.Snake == index)
{
bestOwnDistance = Math.Min(bestOwnDistance, tile.Distance);
}
}
protected override float ScoreDetail(CachedMultiMetricState state, int index)
{
var me = state.World.Snakes[index];
float score = 0.0f;
var fill = Util.CountBasicFloodFill(state.World, me.Head);
var deltaLengthScore = 12.0f * deltaLengthFoodMetric.Score(state.World, index, fill);
var controlScore = 1.0f * controlMetric.Score(state, index);
var hungerScore = 10.0f * hungerPressureMetric.Score(state, index);
var distanceTailScore = TailScoreMultiplier * distanceToOwnTailMetric.ScoreCached(state, index);
score += deltaLengthScore
+ controlScore
+ hungerScore
+ (me.MaxLength > 6 ? distanceTailScore : 0.0f);
return(score);
}
public float Score(CachedMultiMetricState s, int index)
{
var adversarialFill = s.AdversarialFill.EmptyCounts;
int friendlyCounter = adversarialFill[index];
int sum = 0;
for (int i = 0; i < adversarialFill.Count; ++i)
{
sum += adversarialFill[i];
}
if (sum == 0)
{
return(0.0f);
}
float score = ((friendlyCounter / (float)sum) - 0.5f) * 2.0f;
Debug.Assert(!float.IsNaN(score));
return(score);
}
protected abstract float ScoreDetail(CachedMultiMetricState state, int index);
public bool IsTerminal(CachedMultiMetricState state)
{
return(state.World.IsDecided || !state.World.Snakes[BountySnake].Alive);
}