Advent of Code 2021 - Day 10

aoc_2021_10.py

closers = {
  '[': ']',
  '(': ')',
  '<': '>',
  '{': '}'
}

illegals = {
  ']': 0,
  ')': 0,
  '>': 0,
  '}': 0
}

score_values = {
  ']': 2,
  ')': 1,
  '>': 4,
  '}': 3
}

scores = []

for line in input_:

  should_be_next = []

  for char in line:
    if char in closers.keys():
      should_be_next.insert(0, closers[char])

    else:
      if char == should_be_next[0]:
        del should_be_next[0]
      else:
        illegals[char] += 1
        should_be_next = []
        break
  
  score = 0
  for val in should_be_next:
    score = score * 5 + score_values[val]
  
  if score != 0:
    scores.append(score)

part_1 = illegals[')'] * 3 + illegals[']'] * 57 + illegals['}'] * 1197 + illegals['>'] * 25137
part_2 = sorted(scores)[len(scores) // 2]

print(part_1, part_2)