private IEnumerable <Tuple <ShipType, CellPosition, bool> > GenerateContinuesForDamagedShip(
IList <CellPosition> damagedShipCells, IGameFieldBuilder builder, bool vertical, ShipType ship)
{
if (builder.ShipsLeft[ship] == 0)
{
yield break;
}
var topLeftCell = damagedShipCells.Min();
var delta = vertical ? CellPosition.DeltaDown : CellPosition.DeltaRight;
var start = vertical
? new CellPosition(0, topLeftCell.Column)
: new CellPosition(topLeftCell.Row, 0);
for (; builder.Contains(start); start += delta)
{
if (!builder.CanBeAddedSafely(ship, start, vertical, x => OpponentFieldKnowledge[x] != false))
{
continue;
}
var newShipCells = Enumerable.Range(0, ship.GetLength()).Select(x => start + delta * x).ToList();
if (damagedShipCells.Any(x => !newShipCells.Contains(x)))
{
continue;
}
yield return(Tuple.Create(ship, start, vertical));
}
}
private bool TryAddAllShips(IList <ShipType> ships, Predicate <CellPosition> canUseCell)
{
if (!ships.Any())
{
return(true);
}
var ship = ships.Last();
ships.RemoveAt(ships.Count - 1);
var availablePlaces = builder.EnumeratePositions()
.SelectMany(position => new[]
{
new { Position = position, Vertical = true },
new { Position = position, Vertical = false }
})
.Where(x => builder.CanBeAddedSafely(ship, x.Position, x.Vertical, canUseCell))
.Shuffle();
foreach (var place in availablePlaces)
{
builder.TryAddFullShip(ship, place.Position, place.Vertical);
if (TryAddAllShips(ships, canUseCell))
{
return(true);
}
builder.TryRemoveFullShip(ship, place.Position, place.Vertical);
}
ships.Add(ship);
return(false);
}