Anders Englöf Ytterström
e75670eaf2
A good day to utilize lots of unit testing! For pt 2, the code initially tried to reverse the scramble algorithm. The final code however got the unscrambled version by the traditional method most password crackers would resolve to: basic brute forcing with permutations as a list of candidates.
64 lines
2 KiB
Python
64 lines
2 KiB
Python
import re
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from itertools import permutations
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from output import ints
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def solve(data):
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data = [line.strip() for line in data.splitlines()]
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p1 = scramble(data, "abcdefgh")
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p2 = unscramble(data, "fbgdceah")
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return p1, p2
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def scramble(data, subject):
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r_swap = r"(?:letter|position) (.)"
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for line in data:
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if line.startswith("rotate right"):
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x = ints(line)[0]
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subject = subject[-x:] + subject[:-x]
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if line.startswith("rotate left"):
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x = ints(line)[0]
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subject = subject[x:] + subject[:x]
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if line.startswith("rotate based"):
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x = re.findall(r"letter (.)", line)[0]
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i = subject.index(x)
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j = i + 1 % len(subject)
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subject = subject[-j:] + subject[:-j]
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if i >= 4:
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subject = subject[-1:] + subject[:-1]
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if line.startswith("swap letter"):
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x, y = re.findall(r_swap, line)
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subject = subject.replace(y, "#")
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subject = subject.replace(x, y)
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subject = subject.replace("#", x)
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if line.startswith("swap position"):
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x, y = ints(line)
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v1, v2 = subject[x], subject[y]
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subject = subject[:x] + v2 + subject[x + 1 :]
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subject = subject[:y] + v1 + subject[y + 1 :]
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if line.startswith("move"):
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x, y = ints(line)
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v = subject[x]
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subject = subject[:x] + subject[x + 1 :]
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subject = subject[:y] + v + subject[y:]
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if line.startswith("reverse"):
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x, y = ints(line)
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subject = subject[:x] + subject[x : y + 1][::-1] + subject[y + 1 :]
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return subject
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def unscramble(data, T):
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for candidate in ["".join(c) for c in permutations(T)]:
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if scramble(data, candidate) == T:
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return candidate
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if __name__ == "__main__":
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with open("./input/21.txt", "r") as f:
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inp = f.read().strip()
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p1, p2 = solve(inp)
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print(p1)
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print(p2)
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