Bruno BELANYI
acfc841539
This is mostly about unused imports. A couple errors remain, but are fine in my book (using `l` as a variable name, assigning a lambda to a variable).
82 lines
2 KiB
Python
Executable file
82 lines
2 KiB
Python
Executable file
#!/usr/bin/env python
|
|
|
|
import sys
|
|
from typing import Iterator, List, Optional
|
|
|
|
|
|
def solve(input: List[str]) -> int:
|
|
def find_illegal_char(input: str) -> Optional[int]:
|
|
chunks: List[str] = []
|
|
ends_to_start = {
|
|
")": "(",
|
|
"]": "[",
|
|
"}": "{",
|
|
">": "<",
|
|
}
|
|
|
|
for i, c in enumerate(input):
|
|
# Is it a chunk beginning
|
|
if c not in ends_to_start:
|
|
chunks.append(c)
|
|
continue
|
|
# Is it matching the last element on the chunk stack
|
|
current = chunks.pop()
|
|
# If not, corruption has been found
|
|
if ends_to_start[c] != current:
|
|
return i
|
|
|
|
return None
|
|
|
|
def complete_line(input: str) -> str:
|
|
chunks: List[str] = []
|
|
start_to_end = {
|
|
"(": ")",
|
|
"[": "]",
|
|
"{": "}",
|
|
"<": ">",
|
|
}
|
|
|
|
for c in input:
|
|
# Is it a chunk beginning
|
|
if c in start_to_end:
|
|
chunks.append(c)
|
|
continue
|
|
# Otherwise we must match the last open chunk
|
|
assert start_to_end[chunks.pop()] == c # Sanity check
|
|
|
|
return "".join(reversed(list(start_to_end[c] for c in chunks)))
|
|
|
|
def score_completion(completion: str) -> int:
|
|
char_score = {
|
|
")": 1,
|
|
"]": 2,
|
|
"}": 3,
|
|
">": 4,
|
|
}
|
|
|
|
score = 0
|
|
|
|
for c in completion:
|
|
score *= 5
|
|
score += char_score[c]
|
|
|
|
return score
|
|
|
|
def score_completions(completions: Iterator[str]) -> int:
|
|
scores = sorted(map(score_completion, completions))
|
|
return scores[len(scores) // 2]
|
|
|
|
incomplete_lines = filter(lambda line: find_illegal_char(line) is None, input)
|
|
completions = map(complete_line, incomplete_lines)
|
|
|
|
return score_completions(completions)
|
|
|
|
|
|
def main() -> None:
|
|
input = [line.strip() for line in sys.stdin.readlines()]
|
|
print(solve(input))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|