Solve day8

day8/part2.py

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+from functools import reduce
+from math import prod, sqrt
+from pathlib import Path
+from typing import TypeAlias
+
+Point: TypeAlias = tuple[int, int, int]
+
+FILE = "input.txt"
+
+class Circuit:
+    def __init__(self, points: set[Point]) -> None:
+        self.points: set[Point] = points
+
+    def __contains__(self, other: Circuit) -> bool:
+        for p in other.points:
+            if p in self.points: return True
+        return False
+
+    def merge(self, other: Circuit) -> Circuit:
+        return Circuit(self.points.union(other.points))
+
+def main():
+    lines = Path(FILE).read_text().splitlines()
+    points: list[Point] = [parse_point(line) for line in lines]
+    distances = sorted([
+        (distance(p1, p2), Circuit({p1, p2}))
+        for i, p1 in enumerate(points)
+        for p2 in points[i+1:]
+    ], key=lambda x: x[0])
+    big_circuits: list[Circuit] = []
+    last = None
+    for (_, small_circuit) in distances:
+        last = small_circuit
+        new_circuits: list[Circuit] = []
+        for big_circuit in big_circuits:
+            if small_circuit in big_circuit:
+                new_circuits.append(big_circuit)
+        if len(new_circuits):
+            for circuit in new_circuits: big_circuits.remove(circuit)
+            new_circuits.append(small_circuit)
+            new_circuit = reduce(lambda a, b: a.merge(b), new_circuits)
+            big_circuits.append(new_circuit)
+        else:
+            big_circuits.append(small_circuit)
+        if len(big_circuits) == 1 and len(big_circuits[0].points) == len(points):
+            break
+    assert last is not None
+    return prod(p[0] for p in last.points)
+
+
+def distance(p1: tuple[int, int, int], p2: tuple[int, int, int]):
+    x1, y1, z1 = p1
+    x2, y2, z2 = p2
+    return sqrt((x2-x1)**2+(y2-y1)**2+(z2-z1)**2)
+
+
+def parse_point(line: str) -> Point:
+    x, y, z = line.split(",")
+    return (int(x), int(y), int(z))
+
+
+if __name__ == "__main__":
+    print(main())