blob: bed2825524ffb7168e24047e459efef2da4ba638 (
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
|
with open("input") as f:
data = f.read()
blocks = []
last_file_id = None
for idx, count in enumerate(data):
block_char = "." if idx % 2 == 1 else str(idx // 2)
for ii in range(int(count)):
blocks.append(block_char)
last_file_id = block_char
end_seek_idx = len(blocks) - 1
for file in range(int(last_file_id), -1, -1):
file_block = str(file)
file_start_block = None
file_end_block = None
for idx in range(end_seek_idx, -1, -1):
if blocks[idx] == file_block:
if file_end_block is None:
file_end_block = idx
else:
if file_end_block is not None:
file_start_block = idx + 1
end_seek_idx = idx
break
else:
break
file_size = file_end_block - file_start_block + 1
empty_block_size = 0
for idx, block_content in enumerate(blocks):
if idx > end_seek_idx:
break
if block_content == ".":
empty_block_size += 1
else:
empty_block_size = 0
if empty_block_size == file_size:
empty_block_start = idx - file_size + 1
for ii in range(file_size):
blocks[empty_block_start + ii], blocks[file_start_block + ii] = blocks[file_start_block + ii], blocks[empty_block_start + ii]
break
def calculate_checksum(blocks: list[str]):
checksum = 0
for index, elem in enumerate(blocks):
if elem == ".":
continue
checksum += index * int(elem)
return checksum
print(calculate_checksum(blocks))
|
