Anders Englöf Ytterström
fcbeb4bfdd
To solve this, it was easier to visualize the graph and spot errors. This code is kept for reference. To learn the mechanics, These subreddit threads are helpful: - https://www.reddit.com/r/adventofcode/comments/1hla5ql/2024_day_24_part_2_a_guide_on_the_idea_behind_the/ - https://www.reddit.com/r/adventofcode/comments/1hneuf0/2024_day_24_part_2_finally_solved_it/
72 lines
1.8 KiB
Python
72 lines
1.8 KiB
Python
import graphviz
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import re
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def solve(data):
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values, wires = data.split("\n\n")
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values = dict([tuple(c.strip().split(": ")) for c in values.splitlines()])
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wires = [w.split() for w in wires.splitlines()]
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Q = [*wires]
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while Q:
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a, o, b, _, c = Q.pop(0)
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if a not in values or b not in values:
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Q.append((a, o, b, "_", c))
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continue
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a, b = int(values[a]), int(values[b])
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match o:
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case "AND":
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values[c] = int(a + b == 2)
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case "XOR":
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values[c] = int(a + b == 1)
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case "OR":
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values[c] = int(a + b > 0)
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p1 = int(
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"".join(
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[
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str(v)
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for k, v in sorted(values.items(), key=lambda x: x[0], reverse=True)
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if k.startswith("z")
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]
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),
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2,
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)
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# render_graph(wires)
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wrong_xors_inputs = r"[^y|x]\S{2}+ XOR [^x|y]\S{2}+ -> ([^z]\S{2})"
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wrong_z_outputs = r"\s(?:OR|AND) .+ -> (z\d{2})"
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found_manually = ["jqf", "skh"]
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p2 = ",".join(
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sorted(
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[seq for seq in re.findall(wrong_z_outputs, data) if not seq.endswith("45")]
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+ list(re.findall(wrong_xors_inputs, data))
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+ found_manually
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)
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)
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return p1, p2
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def render_graph(wires):
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dot = graphviz.Digraph(comment="The Round Table")
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for a, o, b, _, c in wires:
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ol = f"{a}{b}{o}{c}"
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dot.node(a)
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dot.node(b)
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dot.node(c)
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dot.node(ol, label=o, shape="diamond")
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dot.edge(a, ol)
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dot.edge(b, ol)
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dot.edge(ol, c)
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dot.render("2024.24.p2.gv").replace("\\", "/")
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if __name__ == "__main__":
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with open("./input/24.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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