private void Dfs(Map map, List<Directions> history)
{
var maxPrefixForDir = new Tuple<int, int>[dirs.Length];
for (int i = 0; i < dirs.Length; i++)
maxPrefixForDir[i] = Tuple.Create(-1, i);
for (int i = 0; i < 1; i++)
{
var directions = phrases.AsDirections[i];
for (int j = Math.Min(directions.Length - 1, history.Count); j >= 0; j--)
{
bool eq = true;
for (int k = 0; k < j && eq; k++)
if (directions[k] != history[history.Count - j + k])
eq = false;
if (eq && map.IsGoodPath(directions.Skip(j)))
{
int index = (int)directions[j];
var pair = maxPrefixForDir[index];
if (j >= pair.Item1)
maxPrefixForDir[index] = Tuple.Create(j, pair.Item2);
break;
}
}
}
var dirsOrder = Enumerable.Range(0, dirs.Length).OrderByDescending(i => maxPrefixForDir[i]);
foreach (var d in dirsOrder)
DfsStep(map, (Directions)d, history);
}
public Tuple<int, IEnumerable<Directions>> GetSpellLengthAndPath(Map map, UnitPosition target)
{
Tuple<int, IEnumerable<Directions>> best = null;
int bestCost = -1;
foreach (var sequence in GenerateSpellsSequences())
{
var midPositions = new UnitPosition[sequence.Count];
var finish = target;
for (int i = 0; i < sequence.Count; i++)
midPositions[i] = finish = GetMidPositionByPhrase(finish, sequence[i], map.Unit.Unit.Period);
var path = dfsFinder.GetSpellLengthAndPath(map, finish);
if (path?.Item2 == null)
continue;
var maps = midPositions.Select(p => new Map(map.Id, map.Filled, new PositionedUnit(map.Unit.Unit, p),
map.NextUnits, map.UsedPositions, map.Scores)).ToArray();
bool ok = true;
for (int i = 0; i < sequence.Count && ok; i++)
ok &= maps[i].IsGoodPath(sequence[i]);
if (!ok)
continue;
var result = path.Item2.Concat(((IEnumerable<Directions[]>)sequence).Reverse().SelectMany(s => s)).ToArray();
if (map.IsGoodPath(result))
{
if (!ChooseCarefully)
return Tuple.Create<int, IEnumerable<Directions>>(0, result);
var originalPhrase = phrases.ToOriginalPhrase(result.ToPhrase());
int cost = phrases.GetPowerScoreWithoutUniqueBonus(originalPhrase);
if (cost > bestCost)
{
bestCost = cost;
best = Tuple.Create<int, IEnumerable<Directions>>(0, result);
}
}
}
if (best == null)
best = dfsFinder.GetSpellLengthAndPath(map, target);
return best;
}