lachie.tngl.sh
my advent of code solutions for twenty-twenty-five, written (badly) in python
advent-of-code
python
Solve day 8
+114
-1
+92
day8.py
+92
day8.py
···
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import math
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from util import Vector3
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def parse_data(input_data: str) -> list[Vector3]:
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lines = input_data.splitlines()
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junctions = []
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for line in lines:
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coords = [int(x) for x in line.split(",")]
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junctions.append(Vector3(*coords))
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return junctions
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def part_1(junctions: list[Vector3], connection_count: int) -> str | None:
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distances = Vector3.calculate_distances(junctions)
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distances.sort(key=lambda x: x[2]) # sort from shortest to longest
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circuits = []
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for a, b, _ in distances[:connection_count]:
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add_connection(a, b, circuits)
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circuit_sizes = sorted(list(len(c) for c in circuits), reverse=True)
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return str(math.prod(circuit_sizes[:3]))
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def part_2(junctions: list[Vector3]) -> str | None:
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distances = Vector3.calculate_distances(junctions)
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distances.sort(key=lambda x: x[2]) # sort from shortest to longest
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circuits = []
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visited = set()
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while len(visited) < len(junctions) or len(circuits) > 1:
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a, b, _ = distances.pop(0)
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add_connection(a, b, circuits)
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visited.update((a, b))
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return str(a.x * b.x)
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def remove_circuit_containing(
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v: Vector3, *, circuits: list[set[Vector3]]
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) -> set[Vector3] | None:
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index = next((i for i, elem in enumerate(circuits) if v in elem), -1)
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if index == -1:
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return None
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return circuits.pop(index)
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def add_connection(v1: Vector3, v2: Vector3, circuits: list[set[Vector3]]):
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circuit_a = remove_circuit_containing(v1, circuits=circuits) or {v1}
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circuit_b = remove_circuit_containing(v2, circuits=circuits) or {v2}
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circuits.append(circuit_a | circuit_b)
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def solve(input_data: str, use_example: bool = False) -> tuple[str | None, str | None]:
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puzzle_data = parse_data(input_data)
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return part_1(puzzle_data, 10 if use_example else 1000), part_2(puzzle_data)
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examples = [
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{
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"input": """162,817,812
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57,618,57
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906,360,560
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592,479,940
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352,342,300
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466,668,158
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542,29,236
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431,825,988
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739,650,466
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52,470,668
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216,146,977
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819,987,18
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117,168,530
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805,96,715
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346,949,466
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970,615,88
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941,993,340
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862,61,35
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984,92,344
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425,690,689""",
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"part_1": "40",
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"part_2": "25272",
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}
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]
+22
-1
util.py
+22
-1
util.py
···
1
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from __future__ import annotations
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import enum
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from typing import Any, Iterator, NamedTuple, Self
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import math
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from dataclasses import dataclass
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from itertools import combinations
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from typing import Any, Iterable, Iterator, NamedTuple, Self
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class Tree[T]:
···
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if isinstance(other, Direction):
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return move_pos(self, other)
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raise NotImplementedError()
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@dataclass(frozen=True)
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class Vector3:
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x: int
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y: int
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z: int
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def distance_to(self, other: Vector3) -> float:
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return math.sqrt(
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(other.x - self.x) ** 2 + (other.y - self.y) ** 2 + (other.z - self.z) ** 2
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)
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@staticmethod
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def calculate_distances(
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vectors: Iterable[Vector3],
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) -> list[tuple[Vector3, Vector3, float]]:
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return [(v1, v2, v1.distance_to(v2)) for v1, v2 in combinations(vectors, 2)]