AdventOfCode/2019/day15.py
2019-12-15 11:31:19 +01:00

126 lines
3.3 KiB
Python

from collections import defaultdict
from intcode import Intcode
def main():
with open("day15.txt", "rt") as input_file:
text = input_file.readlines()[0].rstrip()
codes = Intcode.parse_input(text)
droid = Droid(codes)
droid.run()
print(f"Oxygen system at {droid.oxygen_system_pos}.")
parents = bfs(droid.tiles, (0, 0), droid.oxygen_system_pos)
num_steps = len_backtrack(parents, droid.oxygen_system_pos, (0, 0))
print(f"{num_steps} steps with BFS.")
class Droid(Intcode):
TILE_UNK = 0
TILE_WALL = 1
TILE_CLR = 2
RES_COLL = 0
RES_OK = 1
RES_END = 2
DIR_N = 1, (+1, 0)
DIR_S = 2, (-1, 0)
DIR_W = 3, (0, -1)
DIR_E = 4, (0, +1)
NEXT_DIR = {
DIR_N: DIR_E,
DIR_S: DIR_W,
DIR_W: DIR_N,
DIR_E: DIR_S,
}
PREV_DIR = {v: k for k, v in NEXT_DIR.items()}
def __init__(self, codes):
super().__init__(codes)
self.tiles = defaultdict(lambda: defaultdict(lambda: Droid.TILE_UNK))
self.x = 0
self.y = 0
self.steps = 0
self.oxygen_system_pos = None
self.dir = Droid.DIR_N
def input_data(self):
self.steps += 1
return self.dir[0]
def output_data(self, data):
fx, fy = self.get_forward_pos()
if data == Droid.RES_COLL:
self.tiles[fx][fy] = Droid.TILE_WALL
self.dir = Droid.NEXT_DIR[self.dir]
elif data == Droid.RES_OK:
self.halt = (fx, fy) == (0, 0)
self.x, self.y = fx, fy
self.tiles[fx][fy] = Droid.TILE_CLR
self.dir = Droid.PREV_DIR[self.dir]
elif data == Droid.RES_END:
self.x, self.y = fx, fy
self.oxygen_system_pos = self.x, self.y
if self.halt or self.steps % 100 == 0:
self.draw()
def get_forward_pos(self):
return Droid.forward((self.x, self.y), self.dir[1])
@staticmethod
def forward(pos, dirv):
return pos[0] + dirv[0], pos[1] + dirv[1]
def draw(self):
for x in range(-24, 24):
for y in range(-24, 24):
if (x, y) == self.oxygen_system_pos:
print("X", end="")
if (x, y) == (0, 0):
print("s", end="")
elif (x, y) == (self.x, self.y):
print("D", end="")
else:
print({
Droid.TILE_UNK: " ",
Droid.TILE_WALL: "",
Droid.TILE_CLR: "",
}[self.tiles[x][y]], end="")
print()
def bfs(tiles, start, end):
discovered = defaultdict(lambda: defaultdict(bool))
discovered[start[0]][start[1]] = True
parents = {}
q = [start]
while q:
pos = q.pop(0)
if pos == end:
return parents
adjacent = filter(
lambda p: tiles[p[0]][p[1]] != Droid.TILE_WALL,
[Droid.forward(pos, d[1]) for d in Droid.NEXT_DIR.keys()]
)
for adj in adjacent:
if discovered[adj[0]][adj[1]]:
continue
discovered[adj[0]][adj[1]] = True
parents[adj] = pos
q.append(adj)
def len_backtrack(parents, x, end):
count = 0
while x != end:
x = parents[x]
count += 1
return count
if __name__ == "__main__":
main()