static void Main(string[] args)
{
//var originalCode = File.ReadAllText("input.txt").Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(long.Parse).ToArray();
//var extendedCode = new long[1000000];
//Array.Copy(originalCode, extendedCode, originalCode.Length);
//IntCode computer = new IntCode(extendedCode);
//computer.Process(2);
//Console.WriteLine(computer.GetOutput());
//var originalCode = File.ReadAllText("input.txt").Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(long.Parse).ToArray();
//var extendedCode = new long[1000000];
//Array.Copy(originalCode, extendedCode, originalCode.Length);
//var robot = new Robot(extendedCode);
//Console.WriteLine(robot.Solve1());
Moon[] moons = new Moon[4];
int i = 0;
foreach (string line in File.ReadLines("input.txt"))
{
var moon = new Moon();
moon.Parse(line);
moons[i++] = moon;
}
Console.WriteLine(Day12.Solve2(moons));
}
public void ApplyAllGravity(Moon moon)
{
if (x < moon.x)
{
vx++;
}
else if (x > moon.x)
{
vx--;
}
if (y < moon.y)
{
vy++;
}
else if (y > moon.y)
{
vy--;
}
if (z < moon.z)
{
vz++;
}
else if (z > moon.z)
{
vz--;
}
}
public void Gravitate(Moon other)
{
// If other == this, we automatically skip, because positions are equal
for (int i = 0; i < 3; i++)
{
if (this.pos[i] < other.pos[i])
{
v[i]++;
}
if (this.pos[i] > other.pos[i])
{
v[i]--;
}
}
}
private static string ConcatAxisState(string init, Moon m, int axis)
{
if (axis == 0)
{
init += m.x + " ";
init += m.vx + " ";
return(init);
}
if (axis == 1)
{
init += m.y + " ";
init += m.vy + " ";
return(init);
}
init += m.z + " ";
init += m.vz + " ";
return(init);
}
public void ApplyGravity(Moon moon, int i)
{
if (i == 0)
{
if (x < moon.x)
{
vx++;
}
else if (x > moon.x)
{
vx--;
}
}
if (i == 1)
{
if (y < moon.y)
{
vy++;
}
else if (y > moon.y)
{
vy--;
}
}
if (i == 2)
{
if (z < moon.z)
{
vz++;
}
else if (z > moon.z)
{
vz--;
}
}
}
public static long Solve2(Moon[] moons)
{
Moon[] initialMoons = new Moon[4];
for (int i = 0; i < 4; i++)
{
initialMoons[i] = new Moon
{
PosX = moons[i].PosX,
PosY = moons[i].PosY,
PosZ = moons[i].PosZ
};
}
var positionFoundX = 0;
var positionFoundY = 0;
var positionFoundZ = 0;
for (int i = 1; ; i++)
{
ApplyGravity(moons);
UpdatePosition(moons);
int foundOk = 0;
for (int j = 0; j < 4; j++)
{
if (moons[j].PosX == initialMoons[j].PosX && moons[j].VelocityX == 0)
{
foundOk++;
}
}
if (foundOk == 4)
{
positionFoundX = i;
break;
}
}
for (int i = 0; i < 4; i++)
{
moons[i] = new Moon
{
PosX = initialMoons[i].PosX,
PosY = initialMoons[i].PosY,
PosZ = initialMoons[i].PosZ
};
}
for (int i = 1;; i++)
{
ApplyGravity(moons);
UpdatePosition(moons);
int foundOk = 0;
for (int j = 0; j < 4; j++)
{
if (moons[j].PosY == initialMoons[j].PosY && moons[j].VelocityY == 0)
{
foundOk++;
}
}
if (foundOk == 4)
{
positionFoundY = i;
break;
}
}
for (int i = 0; i < 4; i++)
{
moons[i] = new Moon
{
PosX = initialMoons[i].PosX,
PosY = initialMoons[i].PosY,
PosZ = initialMoons[i].PosZ
};
}
for (int i = 1; ; i++)
{
ApplyGravity(moons);
UpdatePosition(moons);
int foundOk = 0;
for (int j = 0; j < 4; j++)
{
if (moons[j].PosZ == initialMoons[j].PosZ && moons[j].VelocityZ == 0)
{
foundOk++;
}
}
if (foundOk == 4)
{
positionFoundZ = i;
break;
}
}
var lcm = determineLCM(positionFoundX, positionFoundY);
return(determineLCM(lcm, positionFoundZ));
}
static void Main(string[] args)
{
System.Console.WriteLine("Day 12");
// Part 1
Moon[] moon = new Moon[] { new Moon(15, -2, -6),
new Moon(-5, -4, -11),
new Moon(0, -6, 0),
new Moon(5, 9, 6) };
for (int t = 0; t < 1000; t++)
{
for (int m = 0; m < moon.Length; m++)
{
for (int n = 0; n < moon.Length; n++)
{
moon[m].Gravitate(moon[n]);
}
}
foreach (Moon m in moon)
{
m.Move();
}
}
int E = 0;
foreach (Moon m in moon)
{
E += m.GetTotalEnergy();
}
System.Console.WriteLine($"1. {E}");
// Part 2
// int[] X = new int[] { -1, 2, 4, 3 };
// int[] Y = new int[] { 0, -10, -8, 5 };
// int[] Z = new int[] { 2, -7, 8, -1 };
int[] X = new int[] { 15, -5, 0, 5 };
int[] Y = new int[] { -2, -4, -6, 9 };
int[] Z = new int[] { -6, -11, 0, 6 };
long[] period = new long[3];
period[0] = GetPeriod(X);
System.Console.WriteLine($"{period[0]}");
period[1] = GetPeriod(Y);
System.Console.WriteLine($"{period[1]}");
period[2] = GetPeriod(Z);
System.Console.WriteLine($"{period[2]}");
long lcm1 = lcm(period[0], period[1]);
long lcm2 = lcm(lcm1, period[2]);
System.Console.WriteLine($"2. {lcm2}");
long GetPeriod(int[] pos)
{
int[] u = new int[4];
for (int i = 0; i < 4; i++)
{
u[i] = pos[i];
}
int[] v = new int[] { 0, 0, 0, 0 };
for (long t = 0; t < Int64.MaxValue; t++)
{
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
if (u[i] < u[j])
{
v[i]++;
}
if (u[i] > u[j])
{
v[i]--;
}
}
}
for (int i = 0; i < 4; i++)
{
u[i] += v[i];
}
bool match = true;
for (int i = 0; i < 4; i++)
{
if (u[i] != pos[i] || v[i] != 0)
{
match = false;
}
}
if (match)
{
return(t + 1);
}
}
return(-1);
}
}