Advent of Code (2019) Day Solution Day 1: The Tyranny of the Rocket Equation Code Day 2: 1202 Program Alarm Code Day 3: Crossed Wires Code Day 4: Secure Container Code Day 5: Sunny with a Chance of Asteroids Code Day 6: Universal Orbit Map Code Day 7: Amplification Circuit Code Day 8: Space Image Format Code Day 9: Sensor Boost Code Day 10: Monitoring Station Code Day 11: Space Police Code Day 12: The N-Body Problem Code Day 13: Care Package Code Day 14: Space Stoichiometry Code Day 15: Oxygen System Code Day 16: Flawed Frequency Transmission Code Day 17: Set and Forget Code Day 18: Many-Worlds Interpretation Code Day 19: Tractor Beam Code Day 20: Donut Maze Code Day 21: Springdroid Adventure Code Day 22: Slam Shuffle Code Day 23: Category Six Code Day 24: Planet of Discord Code Day 25: Cryostasis Code