My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add solution for 2023/13
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+51
2023/day13.py
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2023/day13.py
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import fileinput
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from utils import transposed
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def find_reflections(pattern):
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"""Returns all possible reflections for pattern."""
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sols = []
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# First try solving as-is, then transpose for vertical reflections.
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for multiplier in [100, 1]:
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for y in range(len(pattern) - 1):
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bad = False
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for a, b in zip(reversed(pattern[:y+1]), pattern[y+1:]):
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if a != b:
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bad = True
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break
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if not bad:
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sols.append((y + 1) * multiplier)
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pattern = transposed(pattern)
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return sols
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def unsmudge(pattern, reflection):
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for y in range(len(pattern)):
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for x in range(len(pattern[0])):
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cell = pattern[y][x]
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pattern[y][x] = '.' if cell == '#' else '#'
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for new_reflection in find_reflections(pattern):
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if new_reflection != reflection:
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return new_reflection
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pattern[y][x] = cell
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part_1 = 0
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part_2 = 0
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for pattern in ''.join(fileinput.input()).split('\n\n'):
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pattern = [list(x) for x in pattern.splitlines()]
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reflection = solve(pattern)[0]
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part_1 += reflection
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part_2 += unsmudge(pattern, reflection)
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print("Part 1:", part_1)
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print("Part 2:", part_2)
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