My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add solution for 2016/24
+115
+70
2016/day24.py
+70
2016/day24.py
···
1
+
import fileinput
2
+
from collections import deque
3
+
from itertools import combinations, permutations
4
+
5
+
DIRS = [
6
+
(1, 0),
7
+
(-1, 0),
8
+
(0, -1),
9
+
(0, 1)
10
+
]
11
+
12
+
13
+
def valid(grid, x, y):
14
+
try:
15
+
return grid[y][x] != '#'
16
+
except IndexError:
17
+
return False
18
+
19
+
20
+
def bfs(grid, start, goal):
21
+
horizon = deque()
22
+
horizon.append((start, 0))
23
+
seen = set(start)
24
+
25
+
while horizon:
26
+
(x, y), dst = horizon.pop()
27
+
if (x, y) == goal:
28
+
return dst
29
+
30
+
for dx, dy, in DIRS:
31
+
nx, ny = x + dx, y + dy
32
+
if (nx, ny) not in seen and valid(grid, nx, ny):
33
+
horizon.appendleft(((nx, ny), dst + 1))
34
+
seen.add((nx, ny))
35
+
36
+
37
+
def navigate(distances, path, complete=False):
38
+
dst = distances[0, path[0]]
39
+
for i in range(len(path) - 1):
40
+
dst += distances[path[i], path[i+1]]
41
+
42
+
if complete:
43
+
dst += distances[path[-1], 0]
44
+
45
+
return dst
46
+
47
+
48
+
if __name__ == '__main__':
49
+
grid = []
50
+
num_locs = {}
51
+
52
+
for y, line in enumerate(fileinput.input()):
53
+
row = []
54
+
for x, tile in enumerate(line):
55
+
row.append(tile)
56
+
if tile.isdigit():
57
+
num_locs[int(tile)] = (x, y)
58
+
59
+
grid.append(row)
60
+
61
+
distances = {}
62
+
max_num = max(num_locs)
63
+
64
+
for a, b in combinations(range(max(num_locs) + 1), 2):
65
+
dst = bfs(grid, num_locs[a], num_locs[b])
66
+
distances[a, b] = distances[b, a] = dst
67
+
68
+
paths = list(permutations(range(1, max_num + 1)))
69
+
print "Fewest steps to visit all numbers:", min(navigate(distances, path) for path in paths)
70
+
print "Fewest steps to also return to 0:", min(navigate(distances, path, complete=True) for path in paths)
+43
2016/inputs/24.txt
+43
2016/inputs/24.txt
···
1
+
#####################################################################################################################################################################################
2
+
#...........#...#.....#.....#.....#....7#.................#.............#.....#.#.#...#.#.#.......#.......#.........#.....#.....#...#.....#.#.#.....#.......#.#.....#.....#.#.......#
3
+
#.#####.###.#####.###.#.#.#.#.#.#.#.###.###.#.#.#######.###.#.#####.#.#.#.#.###.#.#.#.#.#.#.#####.#.#.###.#.###.#.#.#.###.#.#.###.#.#.#####.#.#.#.#.#####.###.#.#.###.#.#.#.#.#.###.#
4
+
#.......#...#...#.#.....#.#.#...#...#...#.....#...#.......#.......#.......#.#.....#.#.....#.........#...#...#.#...#.#.#.....#.....#.......#.#...#.#.......#...#.#...#.#...#.#.#.....#
5
+
#.#.#.###.#.#.#.###.###.#.#.###.#.###.#.#.#.###.#.#.#.#.#.#######.#.#####.#.#.###.#.#.###.#.#.#####.#.#.#####.#.#.#.#.#.#.#.#.#.#####.#.#.###.#.#.#.###.###.#.#.#.#.#.#.#.#.#.#.#.#.#
6
+
#...........#.#.....#.....#...#...#.#.....#.#.#.........#.....#...#...#...#...#...#.#.....#.#.....#...#.........#...#.........#.#.#...............#.....#.#...#.#...#.#.......#.#...#
7
+
#.#####.###.#.###########.#.#.#.#.#.#.#.###.#.#######.#.#.#.#.#.###.#.#.#.#.#.#.#.###.#.#.#.#########.###.#.#####.#.#############.#.#.#.#.#.#.###.#.#.#.#.###.#.#.#.#.#.#####.#.###.#
8
+
#...#.#.....#....4#.......#...#.......#.......#...#.......#...#.#...#...#...#.....#.#.#...#.....#...#...#...#...#...#.............#...#...#...#...#.#...#.#...#...#.#...#..0#.....#.#
9
+
#.#.#.###.#.#.#.#.###.###.#.###.#####.#.###.#.#.#.#.#####.#.#.###.###.#.###.###.###.###.#.#.#.#.###.#.#.#.#.#.#####.#.#.#####.#.#.###.#.#.#.###.#.#.#.#.###.#.#.#####.#.#.###.#.#.###
10
+
#.#...#...........#...#.....#.#...#.#.#.#.#.......#...........#.....#.....#.#.#.#.......#.#...#.....#.#.......#.....#...#.......#.#.....#.#.#.....#.#.#.#.#.#.#.........#.#...#.#.#.#
11
+
#.#.#.#.#########.###.#.#.###.#.###.#####.###.#.#.#.###.#.#.###.###.###.#.###.#########.#.###.#.#.#.#.#.#.#.#.#########.#.#####.#.#####.#.#.###.#.#.#.#.#.#####.###.#.#.#.###.#.#.#.#
12
+
#.#.....#.....#.......#.#...#.....#...........#.#.#.....#...#.#.........#.#.#.#.........#.#.......#.......#...#...#...#...#.#...........#.#.....#.#.......#...........#...#...#.....#
13
+
#.#####.#.#.#.#####.#.#.#.#.#.#.#.#.#.#.#.#.###.###.###.#####.###.###.#.###.#.#.#.###.#######.###.#.#.#.#####.#.#####.#.###.#.#####.#.#.#.#########.#.###.#.#.#.#.#.#.###.#####.###.#
14
+
#.#...#.........#.....#...#.......#...#.#...#.......#...#...#.#.......#.......#...#.....#...........#...#.#.....#.................#.#...#.#.........#.#...#.#.#.#.......#.#.....#...#
15
+
#.#.#.#.#.###.#.#.###.#.#.#.#####.#.###.#.###.###.###.#######.#.###.###.#.###.#.#.###.#.#.#####.###.#.#.#.#.###.#.###.#######.#.#.#.#.#.#.#.#.#.#######.#.#.#.#.###.#.#.#.###.#.#.###
16
+
#.....#.#...#.....#...#.#.#.....#.#.#...#.#.#...........#.....#.#...#.................#.#.#...#.........#.......#.#...#.......#.#.#.....#...#...........#.#...#.........#...........#
17
+
###.#.#.#.#.###.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#####.###.###.#.###.#.#.#.#.###.#.#######.#.#####.###.#.#.#.#.#.#.#####.#.#.#.###.#.#.#######.#.#.#.#####.#.###.#.###.###.#.#.###.#####
18
+
#.#.#.#.#...#.....#...#...#...#...#.#...#.#.#.......#...#.#...............#...#.....#.....#.....#.....#.#.#.......#...#.#.....#.....#.........#...#...#.#.......#...#.....#.....#...#
19
+
#.#.#.#.###.###.#.#.#.#########.#.#.#########.#.#.###.#.#.#.###.#####.###.#.#.#.#.###.#.#.#.#.###.#.#.#.#.#.#.#####.###.#.#.#.###.#.#.#.#.#.#.###.#.#.#.###.#.###.#####.###.#.#.#.#.#
20
+
#.....#.....#.....#.......#...........#...#...#.#.....#.#.......#.......#.#.#.........#.............#...#.#.#.....#.....#...#...#.......#...#.......#...#...#...#....1#.....#...#.#.#
21
+
###.#.#.#######.#.#.#.###.#.#.###.###.#.###.#.#.#.#.#.#.###.###.###.#.#.#.#.#.#.#.#.#####.#####.###.#.###.#.#.#.#.###.###.#.#####.###.#.#.###.###.#######.#.###.###.#.###.#.#.#.###.#
22
+
#...#...#5......#.#...#.......#...#.........#.....#...........#...#.#.......#.#...........#...#.......#.....#.#.......#...#.....#.......#...#.#.................#.....#...#...#.....#
23
+
#.###.#.#.#.#####.#####.#####.###.#.#########.###.###.#.#.#####.#.#.###.#.###.###.#.#.#.#.#.###.#.#######.#.#.#.#.#.###.#.#.###.#.#####.###.#.#.#.###.#.#.###.#.###.#########.#####.#
24
+
#.#.#...#...#.....#.....#.#.....#.#.....#.........#...#...#.....#.#.#.......#.......#.......#...#.........#...#...#.....#.#.#...#.........#.#.#.#.#.....#.#.....#.........#.....#...#
25
+
###.###.###.#.#.#.#.###.#.#.#.#.#.#.#.#.#.#####.#.#.#.#.###.#.#####.#.###.#.#.###.#.#.#.#.#.###.#.#.###.#.#########.#.#####.###.#.###.#####.#.#.#.#.#.#.###.#.#.#.#.#.###.#.#.#.#.#.#
26
+
#.#.#.#.......#...#.#...#.....#.#.................#.#.........#.....#...#...#.#.....#.....#.....#...#...#.....#...#...#...#.#.#...#...#...#...#...#...#.#...#.......................#
27
+
#.###.#############.#.#######.#.###.###########.#.#.###.###.#.#.###.###.#.###.###.#.#.###.#.#.###.#.#.#.###.#.###.#.#.#.#.#.#.#.###.#.#.#.#.#.#.#.#.#.#.#.###.###.#.#.#.#.#.#.#.#.#.#
28
+
#.....#.#.......#...............#.....#...........#...#.#.#...#...#...#.#.#...#.......#...#...#.....#.....#.#.#...............#.#...#.....#.....#.#.#.#.......#...#.#...#...#.....#.#
29
+
#.#.###.#.###.#.#.#######.#.###.#.###.#.#.#.#.#####.#.#.#.#.#.#.#.###.#######.#.#.###.###.#.#.#.#######.#.###.#.#.###########.###.#########.#.#####.#.#.#.#.#.#.#.#.#.#####.###.#.###
30
+
#...#...#.#...............#.#.......#.#...#.#.......#.#...#.#.....#.....#.#.......#.........#.#.#...#.#...................#...#...#.............#.......#.......#.#...#...#.....#.#.#
31
+
#.#.#####.#.#######.#.###.#.#####.#.#.#.#.###.#.#.#.###.#.#.#####.###.###.#.#.#.#.#.#####.#.###.#.#.#.#.###.#.#####.#######.#.###.#.#.#.#.#####.#.#####.###.#######.#.#.#.#.###.#.#.#
32
+
#.........#.#...#.#.......#...#...#...........#.....#.....#.......#.....#.....#.#.#...#.#...#.....#.....#.....#...#.#.........#.....#.....#.#.#.....#...#...#.......#.#.#.....#...#.#
33
+
###.#######.#.#.#.#.###.#.###.#.###.###.#.###.#.#.#.#.#.#.###.#.###.#.#.#.###.###.#.#.#.#.###.#.#.###.#.#.#.#.#.#.#.#.#.#.#####.#####.###.#.#.#.#####.###.###.#.#.#####.#.#####.#.###
34
+
#...#.......#.......#...#...#.........#.....#...#...#...#.#...#.........#...#.....#...#.#.#.#.#...#.....#.#.....#.....#.#.........#.....#.#.#.....#...#...#.......#.#3....#...#.....#
35
+
#.###.###.#####.###.###.###.#.###.#.###.###.#.###.###.#.#.#######.#.#.#.#.###.#.#.#.###.###.#.#.###.#.#.#.#####.###.###.###.#.###.#.#.###.#.#.#####.###.#.#.###.#.#.###.#.#.#.###.#.#
36
+
#.#...#.....#.#...#...#.#...........#...#.#...#.#.#.....#.#.......#.#.....#...#...#.....#...#.......#.........#...#.#...#.#.#.#.....#.....#.......#.........#.....#.....#.#...#.#...#
37
+
#.#.#.#####.#.###########.###.#.#####.###.###.#.###.###.#.#.#####.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.#.###.#.###.#.#.#.#.###.#.#.#.#.#####################.###.###.###.#.#.#.#.#.#
38
+
#.#...#.#...#.....#...#...#.....#.......#.......#.....#.#...#.....#...#.....#...#.......#...#.#...#.#...#.#...........#...#.#...#.#.......#.........#.#.......#...........#...#...#.#
39
+
###.###.#.#.#.#.#.#.#####.#.#.#.###.#.#######.#.###.#.#####.#.###.###.#.#.###.#.#.#.###.#.#######.#.#.#.###.###.#.#######.#.#.#.#.#.#.###.#.#.#.#.#.#.#.#.#.#.###.#.#.###.###.#.#.###
40
+
#.#...#.......#.#...#.#.........#.........#...#.#...#.........#.#...#...#.........#...#.....#.......#...#.....#.....#...........#..2#.....#.#.....#...#.#.....#.......#...#...#...#.#
41
+
#.#.#.#.#.#.#.#.###.#.###.#.###.#.#.###.#.#.#.#.#.#.###.#.#####.#.###.###.#.###.#.#.#.#####.#.#.###.#.###.###.###.#.#####.#.#####.#####.#.#.#.#.#.###.#.#.#####.#.#.#.#.###.#.#.###.#
42
+
#.#..6#.........#...#.#.......#.#.......#.........#...#.....#.#...#...#.#.#.....#.....#.#.........................#.......#...#.#.........#.#...#...........#...#.....#.....#...#...#
43
+
#####################################################################################################################################################################################