public static GameState Start(
GridCell[,] grid,
int elfAttackPower = 3)
{
var gridPair = GridPair.For(grid);
GridOperations.CalculateCloseness(gridPair);
var elfHitPoints = ImmutableDictionary <int, int> .Empty;
var goblinHitPoints = ImmutableDictionary <int, int> .Empty;
int height = gridPair.Primary.GetLength(0);
int width = gridPair.Primary.GetLength(1);
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
GridCell cell = gridPair.Primary[y, x];
if (cell.IsElf)
{
elfHitPoints = elfHitPoints.Add(cell.ElfId.Value, 200);
}
else if (cell.IsGoblin)
{
goblinHitPoints = goblinHitPoints.Add(cell.GoblinId.Value, 200);
}
}
}
return(new GameState(gridPair, elfHitPoints, goblinHitPoints, elfAttackPower));
}
public static (int score, bool totalElfVictory) SolvePart1(string map, bool show = false, int elfAttackPower = 3)
{
int rounds = 0;
GameState g;
int startLine = Console.CursorTop;
bool combatEnds = false;
for (g = GameState.Start(GridOperations.ParseGrid(map), elfAttackPower); !combatEnds; (g, combatEnds) = g.PlayRound())
{
rounds += 1;
if (show)
{
Console.SetCursorPosition(0, startLine);
ShowGrid(g.Grid);
}
}
bool goblinsWon = g.GoblinHitPoints.Any(kv => kv.Value > 0);
int winningTeamHitPointsRemaining = (goblinsWon ? g.GoblinHitPoints : g.ElfHitPoints)
.Select(kv => kv.Value)
.Where(p => p > 0)
.Sum();
return(winningTeamHitPointsRemaining * (rounds - 1), g.ElfHitPoints.All(kv => kv.Value > 0));
}
public (GameState state, bool combatEnds) PlayRound()
{
bool combatEnds = false;
var coordinates = new List <(int x, int y)>();
int height = Grid.GetLength(0);
int width = Grid.GetLength(1);
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
GridCell cell = Grid[y, x];
if (cell.IsElf || cell.IsGoblin)
{
coordinates.Add((x, y));
}
}
}
var elfHitPoints = ElfHitPoints;
var goblinHitPoints = GoblinHitPoints;
GridCell[,] grid = Grid;
for (int i = 0; i < coordinates.Count; ++i)
{
var xy = coordinates[i];
GridCell unitCell = grid[xy.y, xy.x];
if (!(unitCell.IsElf || unitCell.IsGoblin))
{
// Already taken out in an earlier turn this round.
continue;
}
if ((unitCell.IsElf && !goblinHitPoints.Any(kv => kv.Value > 0)) ||
(unitCell.IsGoblin && !elfHitPoints.Any(kv => kv.Value > 0)))
{
combatEnds = true;
break;
}
int hitPower = unitCell.IsElf
? elfHitPoints[unitCell.ElfId.Value]
: goblinHitPoints[unitCell.GoblinId.Value];
// Move if appropriate.
var move = GridOperations.CalculateMove(grid, xy.x, xy.y);
if (move.HasValue)
{
bool isElf = unitCell.IsElf;
int unitId = isElf ? unitCell.ElfId.Value : unitCell.GoblinId.Value;
RemoveItem(height, width, grid, xy);
var newCoordinates = (x : xy.x + move.Value.dx, y : xy.y + move.Value.dy);
grid[newCoordinates.y, newCoordinates.x] = isElf
? GridCell.Elf(unitId)
: GridCell.Goblin(unitId);
GridOperations.CalculateCloseness(_gridPair);
coordinates[i] = newCoordinates;
}
// Attack if appropriate.
xy = coordinates[i];
var match = GridOperations.FindBest(
grid,
xy.x,
xy.y,
c =>
{
bool isTarget = unitCell.IsElf ? c.IsGoblin : c.IsElf;
return(isTarget
? NullIfDead(unitCell.IsElf ? goblinHitPoints[c.GoblinId.Value] : elfHitPoints[c.ElfId.Value])
: default);
int?NullIfDead(int v) => v > 0 ? v : default;
},
