AoC 2018 Day 11: Gridlocked Fuel

Source: Chronal Charge

Part 1: Define a grid as follows (x,y coordinates + a constant C):

  • r(x) = x + 10
  • G(x, y) = hundreds(r(x) * (r(x) * y + C)) - 5

Find the 3x3 area in a 300x300 grid with the highest total G(x, y) .


AoC 2018 Day 9: Marble Madness

Source: Marble Mania

Part 1: Place marbles in a circle such that each marble is placed by skipping one place except for marbles divisible by 23. For those, don’t place them, skip back 7 places, and remove that marble as well. Add these two marbles to your current score.

Given a specific player count and last marble, what’s the highest score?