61 lines
1.5 KiB
Python
61 lines
1.5 KiB
Python
from lib import *
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input = read_input(2016, 21)
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import re
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def scramble(inp):
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(*out,) = inp
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for line in input.splitlines():
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if match := re.match(r"^swap position (\d+) with position (\d+)$", line):
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x, y = map(int, match.groups())
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out[x], out[y] = out[y], out[x]
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if match := re.match(r"^swap letter ([a-zA-Z\d]+) with letter ([a-zA-Z\d]+)$", line):
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x, y = match.groups()
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out = [[[c, x][c == y], y][c == x] for c in out]
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if match := re.match(r"^rotate (left|right) (\d+) steps?$", line):
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d, n = match.groups()
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n = int(n)
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if d == "right":
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n *= -1
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n %= len(out)
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out = out[n:] + out[:n]
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if match := re.match(r"^rotate based on position of letter ([a-zA-Z\d]+)$", line):
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(x,) = match.groups()
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idx = out.index(x)
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n = -(1 + idx + (idx >= 4)) % len(out)
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out = out[n:] + out[:n]
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if match := re.match(r"^reverse positions (\d+) through (\d+)$", line):
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x, y = sorted(map(int, match.groups()))
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out = out[:x] + out[x : y + 1][::-1] + out[y + 1 :]
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if match := re.match(r"^move position (\d+) to position (\d+)$", line):
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x, y = map(int, match.groups())
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out.insert(y, out.pop(x))
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return "".join(out)
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print(scramble("abcdefgh"))
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for it in itertools.permutations("abcdefgh"):
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if scramble(inp := "".join(it)) == "fbgdceah":
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print(inp)
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break
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