advent_of_code/10/10_2.py

#!/usr/bin/env python
# 2021 - Advent Of Code - 10 part 2

def parse_file(file):
    non_corrupted = []
    with open(file, encoding="utf-8") as f:
        i = 0
        for line in f.readlines():
            chunks = []
            corrupted = False
            for c in line.strip():
                if c in close_sign.values():  # open signs
                    chunks.append(c)
                elif c in close_sign:
                    last_open = chunks.pop()
                    if close_sign[c] != last_open:
                        # print(f'found corrupted chunk at line {i}: {line.strip()}')
                        count_score[c] += 1
                        corrupted = True
                        break
            if not corrupted:
                non_corrupted.append(line.strip())
            i += 1
        print(f'nb lines: {i}')

    return non_corrupted


def complete_lines(lines):
    completions = []
    for line in lines:
        chunks = []
        for c in line:
            if c in close_sign.values():  # open signs
                chunks.append(c)
            elif c in close_sign.keys():
                chunks.pop()
        completion = [open_sign[c] for c in reversed(chunks)]
        completions.append(completion)
    return completions


close_sign = {')': '(', ']': '[', '}': '{', '>': '<'}
open_sign = {'(': ')', '[': ']', '{': '}', '<': '>'}
count_score = {')': 0, ']': 0, '}': 0, '>': 0}
score_table = {')': 1, ']': 2, '}': 3, '>': 4}

# sequences = parse_file('input_example.txt')
sequences = parse_file('input.txt')
print(f'nb clean lines: {len(sequences)}')

autocompletions = complete_lines(sequences)

auto_score = []
for a in autocompletions:
    score = 0
    for sign in a:
        score = score * 5 + score_table[sign]
    auto_score.append(score)

score = sorted(auto_score)[int(len(auto_score)/2)]
print(f'middle score: {score}')