public string Solve(string input)
{
string[] inputLines = input.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
int yOffset = inputLines[0].Length;
string map = string.Concat(inputLines);
// Find the minecarts
List <Minecart> minecarts = Minecart.FindInMap(ref map, yOffset);
while (true)
{
// First, sort the minecarts by their position...
minecarts = minecarts.OrderBy(x => x.Position).ToList();
// Now move them all...
foreach (Minecart current in minecarts)
{
current.Position += current.NextMove;
current.SetNextMove(yOffset, map[current.Position]);
// Has it crashed?
if (current.GetCrashedIntoMinecart(minecarts) != null)
{
return($"{current.Position % yOffset},{current.Position / yOffset}");
}
}
}
}
public string Solve(string input)
{
string[] inputLines = input.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
int yOffset = inputLines[0].Length;
string map = string.Concat(inputLines);
// Find the minecarts
List <Minecart> minecarts = Minecart.FindInMap(ref map, yOffset);
// We won't be able to just remove carts from the collection as we go,
// so we keep a list of those that have been removed
var removedCarts = new List <Minecart>();
while (true)
{
// First, sort the minecarts by their position...
minecarts = minecarts.OrderBy(x => x.Position).ToList();
// Now move the ones that haven't crashed...
foreach (Minecart current in minecarts)
{
if (removedCarts.Contains(current))
{
continue;
}
current.Position += current.NextMove;
current.SetNextMove(yOffset, map[current.Position]);
// Has it crashed?
Minecart crashedIntoMinecart = current.GetCrashedIntoMinecart(minecarts.Where(x => !removedCarts.Contains(x)));
if (crashedIntoMinecart != null)
{
removedCarts.Add(current);
removedCarts.Add(crashedIntoMinecart);
}
}
// At the end of the tick - is there only one remaining?
if (minecarts.Count - removedCarts.Count == 1)
{
Minecart lastCart = minecarts.First(x => !removedCarts.Contains(x));
return($"{lastCart.Position % yOffset},{lastCart.Position / yOffset}");
}
}
}