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aoc2019
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optimize day 12
continuous-integration/drone/push Build is passing Details

This commit is contained in:
Ben Harris 2019-12-12 16:27:25 -05:00
parent a0b13e3276
commit 16a5eff3bd
2 changed files with 8 additions and 31 deletions
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4
Day1.cs
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@ -27,8 +27,8 @@ namespace aoc2019
return total;
}
public override string Part1() => $"{masses.Select(FuelCost).Sum()}";
public override string Part1() => $"{masses.Sum(FuelCost)}";
public override string Part2() => $"{masses.Select(FullCost).Sum()}";
public override string Part2() => $"{masses.Sum(FullCost)}";
}
}

35
Day12.cs
View File

@ -109,40 +109,17 @@ namespace aoc2019
public override string Part2()
{
moons = startingPositions;
step = 0;
var seenX = new HashSet<string>();
var seenY = new HashSet<string>();
var seenZ = new HashSet<string>();
int repX = 0, repY = 0, repZ = 0;
int cycleX = 0, cycleY = 0, cycleZ = 0;
while (true)
{
if (repX != 0 && repY != 0 && repZ != 0) break;
while (cycleX == 0 || cycleY == 0 || cycleZ == 0) {
Step();
if (repX == 0)
{
var xcoords = moons.Select(m => (m.x, m.dx)).ToDelimitedString();
if (seenX.Contains(xcoords)) repX = step;
seenX.Add(xcoords);
}
if (repY == 0)
{
var ycoords = moons.Select(m => (m.y, m.dy)).ToDelimitedString();
if (seenY.Contains(ycoords)) repY = step;
seenY.Add(ycoords);
}
if (repZ == 0)
{
var zcoords = moons.Select(m => (m.z, m.dz)).ToDelimitedString();
if (seenZ.Contains(zcoords)) repZ = step;
seenZ.Add(zcoords);
}
step++;
if (cycleX == 0 && moons.All(m => m.dx == 0)) cycleX = step * 2;
if (cycleY == 0 && moons.All(m => m.dy == 0)) cycleY = step * 2;
if (cycleZ == 0 && moons.All(m => m.dz == 0)) cycleZ = step * 2;
}
return $"{LCM(repX, LCM(repY, repZ))}";
return $"{LCM(cycleX, LCM(cycleY, cycleZ))}";
}
}
}