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