public void Part2()
{
const int TargetCycles = 6;
const int Growth = 2 * (TargetCycles + 1);
string[] input = File.ReadAllLines("Inputs/Day17.txt");
IntVec2 inputBounds = (input[0].Length, input.Length);
IntVec4 bounds = (
inputBounds.X + Growth,
inputBounds.Y + Growth,
1 + Growth,
1 + Growth);
(IntVec4 low, IntVec4 high)bounding = (
(TargetCycles, TargetCycles, TargetCycles, TargetCycles),
(inputBounds.X + TargetCycles + 2, inputBounds.Y + TargetCycles + 2, TargetCycles + 2, TargetCycles + 2));
bool[,,,] current = new bool[
bounds.X + 1,
bounds.Y + 1,
bounds.Z + 1,
bounds.W + 1];
bool[,,,] next = (bool[, , , ])current.Clone();
for (int j = 0; j < input.Length; j++)
{
for (int i = 0; i < input[j].Length; i++)
{
current[i + TargetCycles + 1, j + TargetCycles + 1, TargetCycles + 1, TargetCycles + 1] = input[j][i] == '#';
}
}
IntVec4[] dirs = IntVec4.Zero.Surrounding().ToArray();
for (int cycles = 0; cycles < TargetCycles; cycles++)
{
for (int i = bounding.low.X; i <= bounding.high.X; i++)
{
for (int j = bounding.low.Y; j <= bounding.high.Y; j++)
{
for (int k = bounding.low.Z; k <= bounding.high.Z; k++)
{
for (int l = bounding.low.W; l <= bounding.high.W; l++)
{
bool active = current[i, j, k, l];
int adjActive = dirs.Count(adj => current[i + adj.X, j + adj.Y, k + adj.Z, l + adj.W]);
next[i, j, k, l] = active ? adjActive is 2 or 3 : adjActive is 3;
}
}
}
}
(current, next) = (next, current);
bounding = (bounding.low - 1, bounding.high + 1);
}
int answer = 0;
for (int i = 1; i < bounds.X; i++)
{
for (int j = 1; j < bounds.Y; j++)
{
for (int k = 1; k < bounds.Z; k++)
{
for (int l = 1; l < bounds.W; l++)
{
if (current[i, j, k, l])
{
++answer;
}
}
}
}
}
Assert.Equal(2012, answer);
}
public PositionColorKey(Vector3 p, Color c)
{
position = new IntVec3(p);
color = new IntVec4(c);
}
