""" https://adventofcode.com/2019/day/12 """ from itertools import combinations from copy import deepcopy def readFile(): with open(f"{__file__.rstrip('code.py')}input.txt", "r") as f: lines = [line[1:-2].replace(" ", "").split(",") for line in f.readlines()] return [(int(line[0][2:]), int(line[1][2:]), int(line[2][2:])) for line in lines] def cmp(a,b): return 0 if a == b else -1 if a < b else 1 class Moon: def __init__(self, pos): self.pos = [pos[0], pos[1], pos[2]] self.vel = [0] * 3 def changeGravity(self, other): x,y,z = cmp(self.pos[0], other.pos[0]), cmp(self.pos[1], other.pos[1]), cmp(self.pos[2], other.pos[2]) self.vel[0], other.vel[0] = self.vel[0] - x, other.vel[0] + x self.vel[1], other.vel[1] = self.vel[1] - y, other.vel[1] + y self.vel[2], other.vel[2] = self.vel[2] - z, other.vel[2] + z def move(self): self.pos[0] += self.vel[0] self.pos[1] += self.vel[1] self.pos[2] += self.vel[2] def energy(self): pot = abs(self.pos[0]) + abs(self.pos[1]) + abs(self.pos[2]) kin = abs(self.vel[0]) + abs(self.vel[1]) + abs(self.vel[2]) return pot, kin, pot * kin def simulate(moons : list, steps): for i in range(steps): for m, n in list(combinations(moons, 2)): m.changeGravity(n) for moon in moons: moon.move() def part1(vals: list): moons = [Moon((val[0], val[1], val[2])) for val in vals] simulate(moons, 1000) return sum([moon.energy()[2] for moon in moons]) def part2(vals: list): pass def test(): moons = [Moon(p) for p in ((-1,0,2), (2,-10,-7), (4,-8,8), (3,5,-1))] simulate(moons, 10) assert sum([moon.energy()[2] for moon in moons]) == 179 vpos, vvel = ((2,1,-3),(1,-8,0),(3,-6,1),(2,0,4)), ((-3,-2,1),(-1,1,3),(3,2,-3),(1,-1,-1)) for i in range(4): assert vpos[i] == (moons[i].pos[0], moons[i].pos[1] ,moons[i].pos[2]) and \ vvel[i] == (moons[i].vel[0], moons[i].vel[1], moons[i].vel[2]) moons = [Moon(p) for p in ((-8,-10,0), (5,5,10), (2,-7,3), (9,-8,-3))] simulate(moons,100) assert sum([moon.energy()[2] for moon in moons]) == 1940 if __name__ == "__main__": test() vals = readFile() print(f"Part 1: {part1(vals)}") print(f"Part 2: {part2(vals)}")