private string Solve(int lastMarble)
{
var marbles = new MarbleList();
marbles.AddFirst(0);
var currentNode = marbles.First;
var playerScore = new long[PlayerCount];
int currentPlayer = 0;
for (int marble = 1; marble <= lastMarble; marble++)
{
if (marble % 23 == 0)
{
playerScore[currentPlayer] += marble;
currentNode = marbles.Previous(currentNode, 7);
playerScore[currentPlayer] += currentNode.Value;
currentNode = currentNode.Next;
marbles.Remove(currentNode.Previous);
}
else
{
marbles.AddAfter(marbles.Next(currentNode, 1), marble);
currentNode = marbles.Next(currentNode, 2);
}
currentPlayer = (currentPlayer + 1) % PlayerCount;
}
return(playerScore.Max().ToString());
}
