summaryrefslogtreecommitdiff
path: root/2025/day04.py
blob: e69acd538c5b13892c557129abc4ce3a9ea2f9ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
#!/usr/bin/env python3
from functools import reduce
from re import findall
from copy import deepcopy
import sys
# import numpy as np

filename = sys.argv[1] if len(sys.argv) == 2 \
    else "in/" + sys.argv[0].split('/')[-1].rstrip(".py") + ".pzl"
data = open(filename).read()
lines = data.rstrip('\n').split('\n')

res1 = 0
res2 = 0

D = dict()
for x,line in enumerate(lines):
    for y, c in enumerate(line):
        D[(x,y)] = c

for (x, y), c in D.items():
    if c != '@':
        continue
    n = 0
    for dx, dy in [(1, -1), (1, 0), (1, 1), (-1, -1),
                   (-1, 0), (-1, 1), (0, -1), (0, 1)]:
        nx = x + dx
        ny = y + dy
        if (nx, ny) in D and D[(nx, ny)] == '@':
            n += 1
    if n < 4:
        res1 += 1

def remove(D):
    r = 0
    for (x, y), c in D.items():
        if c != '@':
            continue
        n = 0
        for dx, dy in [(1, -1), (1, 0), (1, 1), (-1, -1),
                       (-1, 0), (-1, 1), (0, -1), (0, 1)]:
            nx = x + dx
            ny = y + dy
            if (nx, ny) in D and D[(nx, ny)] == '@':
                n += 1
        if n < 4:
            r += 1
            D[(x, y)] = '.'
    return D, r

D, r = remove(D)
res2 += r
while r > 0:
    D, r = remove(D)
    res2 += r

print('res1:', res1)
print('res2:', res2)