AoC 2017 Day 20

Author: pareronia

README.md

@@ -72,7 +72,7 @@
 <!-- @BEGIN:ImplementationsTable:2017@ -->
 | | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 |
 | ---| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
-| python3 | [✓](src/main/python/AoC2017_01.py) | [✓](src/main/python/AoC2017_02.py) | [✓](src/main/python/AoC2017_03.py) | [✓](src/main/python/AoC2017_04.py) | [✓](src/main/python/AoC2017_05.py) | [✓](src/main/python/AoC2017_06.py) |  | [✓](src/main/python/AoC2017_08.py) |  |  |  |  | [✓](src/main/python/AoC2017_13.py) |  | [✓](src/main/python/AoC2017_15.py) | [✓](src/main/python/AoC2017_16.py) |  |  |  |  |  |  |  |  |  |
+| python3 | [✓](src/main/python/AoC2017_01.py) | [✓](src/main/python/AoC2017_02.py) | [✓](src/main/python/AoC2017_03.py) | [✓](src/main/python/AoC2017_04.py) | [✓](src/main/python/AoC2017_05.py) | [✓](src/main/python/AoC2017_06.py) |  | [✓](src/main/python/AoC2017_08.py) |  |  |  |  | [✓](src/main/python/AoC2017_13.py) |  | [✓](src/main/python/AoC2017_15.py) | [✓](src/main/python/AoC2017_16.py) |  |  |  | [✓](src/main/python/AoC2017_20.py) |  |  |  |  |  |
 | java | [✓](src/main/java/AoC2017_01.java) | [✓](src/main/java/AoC2017_02.java) | [✓](src/main/java/AoC2017_03.java) | [✓](src/main/java/AoC2017_04.java) | [✓](src/main/java/AoC2017_05.java) | [✓](src/main/java/AoC2017_06.java) | [✓](src/main/java/AoC2017_07.java) | [✓](src/main/java/AoC2017_08.java) | [✓](src/main/java/AoC2017_09.java) | [✓](src/main/java/AoC2017_10.java) |  | [✓](src/main/java/AoC2017_12.java) | [✓](src/main/java/AoC2017_13.java) |  | [✓](src/main/java/AoC2017_15.java) | [✓](src/main/java/AoC2017_16.java) | [✓](src/main/java/AoC2017_17.java) | [✓](src/main/java/AoC2017_18.java) | [✓](src/main/java/AoC2017_19.java) | [✓](src/main/java/AoC2017_20.java) |  |  |  |  |  |
 | bash | [✓](src/main/bash/AoC2017_01.sh) | [✓](src/main/bash/AoC2017_02.sh) |  | [✓](src/main/bash/AoC2017_04.sh) | [✓](src/main/bash/AoC2017_05.sh) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
 | c++ | [✓](src/main/cpp/2017/01/AoC2017_01.cpp) | [✓](src/main/cpp/2017/02/AoC2017_02.cpp) | [✓](src/main/cpp/2017/03/AoC2017_03.cpp) | [✓](src/main/cpp/2017/04/AoC2017_04.cpp) | [✓](src/main/cpp/2017/05/AoC2017_05.cpp) |  |  |  |  |  |  |  | [✓](src/main/cpp/2017/13/AoC2017_13.cpp) |  |  |  |  | [✓](src/main/cpp/2017/18/AoC2017_18.cpp) |  |  |  |  |  |  |  |

src/main/python/AoC2017_20.py

@@ -0,0 +1,94 @@
+#! /usr/bin/env python3
+#
+# Advent of Code 2017 Day 20
+#
+from __future__ import annotations
+import re
+from collections import defaultdict
+from typing import NamedTuple
+from aoc import my_aocd
+from aoc.geometry3d import Position3D, Vector3D
+import aocd
+
+
+TICKS = 400
+
+
+class Particle(NamedTuple):
+    number: int
+    position: Position3D
+    velocity: Position3D
+    acceleration: Position3D
+
+    @classmethod
+    def create(cls, number: int, nums: list[int]) -> Particle:
+        assert len(nums) == 9
+        return Particle(
+            number,
+            Position3D(nums[0], nums[1], nums[2]),
+            Position3D(nums[3], nums[4], nums[5]),
+            Position3D(nums[6], nums[7], nums[8]),
+        )
+
+    def next(self) -> Particle:
+        v2 = self.velocity.translate(Vector3D.to_from(self.acceleration))
+        p2 = self.position.translate(Vector3D.to_from(v2))
+        return Particle(self.number, p2, v2, self.acceleration)
+
+    def distance(self) -> int:
+        return self.position.manhattan_distance_to_origin()
+
+
+def _parse(inputs: tuple[str]) -> list[Particle]:
+    return [
+        Particle.create(i, list(map(int, re.findall(r"[-0-9]+", line))))
+        for i, line in enumerate(inputs)
+    ]
+
+
+def part_1(inputs: tuple[str]) -> int:
+    particles = _parse(inputs)
+    for _ in range(TICKS):
+        particles = [p.next() for p in particles]
+    particles.sort(key=lambda p: p.distance())
+    return particles[0].number
+
+
+def part_2(inputs: tuple[str]) -> int:
+    particles = _parse(inputs)
+    for _ in range(TICKS):
+        m = defaultdict(list)
+        [m[pn.position].append(pn) for pn in [p.next() for p in particles]]
+        particles = [p for mv in m.values() for p in mv if len(mv) == 1]
+    return len(m)
+
+
+TEST1 = """\
+p=<3,0,0>, v=<2,0,0>, a=<-1,0,0>
+p=<4,0,0>, v=<0,0,0>, a=<-2,0,0>
+""".splitlines()
+TEST2 = """\
+p=<-6,0,0>, v=< 3,0,0>, a=<0,0,0>
+p=<-4,0,0>, v=< 2,0,0>, a=<0,0,0>
+p=<-2,0,0>, v=< 1,0,0>, a=<0,0,0>
+p=< 3,0,0>, v=<-1,0,0>, a=<0,0,0>
+""".splitlines()
+
+
+def main() -> None:
+    puzzle = aocd.models.Puzzle(2017, 20)
+    my_aocd.print_header(puzzle.year, puzzle.day)
+
+    assert part_1(TEST1) == 0
+    assert part_2(TEST2) == 1
+
+    inputs = my_aocd.get_input(2017, 20, 1_000)
+    result1 = part_1(inputs)
+    print(f"Part 1: {result1}")
+    result2 = part_2(inputs)
+    print(f"Part 2: {result2}")
+    my_aocd.check_results(puzzle, result1, result2)
+
+
+if __name__ == "__main__":
+    main()

src/main/python/aoc/geometry3d.py

@@ -0,0 +1,47 @@
+from __future__ import annotations
+from typing import NamedTuple
+
+
+class Point3D(NamedTuple):
+    x: int
+    y: int
+    z: int
+
+
+class Position3D(Point3D):
+    @classmethod
+    def copy(cls, position: Position3D) -> Position3D:
+        return Position3D.of(position.x, position.y, position.z)
+
+    @classmethod
+    def of(cls, x: int, y: int, z: int) -> Position3D:
+        return Position3D(x, y, z)
+
+    def translate(self, vector: Vector3D, amplitude: int = 1) -> Position3D:
+        return Position3D.of(
+            self.x + vector.x * amplitude,
+            self.y + vector.y * amplitude,
+            self.z + vector.z * amplitude,
+        )
+
+    def manhattan_distance(self, other: Position3D) -> int:
+        return (
+            abs(self.x - other.x)
+            + abs(self.y - other.y)
+            + abs(self.z - other.z)
+        )
+
+    def manhattan_distance_to_origin(self) -> int:
+        return self.manhattan_distance(Position3D.of(0, 0, 0))
+
+
+class Vector3D(Point3D):
+    @classmethod
+    def of(cls, x: int, y: int, z: int) -> Vector3D:
+        return Vector3D(x, y, z)
+
+    @classmethod
+    def to_from(
+        cls, to: Position3D, from_: Position3D = Position3D.of(0, 0, 0)
+    ) -> Vector3D:
+        return Vector3D(to.x - from_.x, to.y - from_.y, to.z - from_.z)

src/test/python/test_geometry3d.py

@@ -0,0 +1,25 @@
+#! /usr/bin/env python3
+#
+
+import unittest
+from aoc.geometry3d import Position3D
+
+
+class TestGeometry3D(unittest.TestCase):
+    def test_manhattan_distance(self):
+        self.assertEqual(
+            Position3D.of(2, 2, 2).manhattan_distance(Position3D.of(0, 0, 0)),
+            6,
+        )
+        self.assertEqual(
+            Position3D.of(2, 2, 2).manhattan_distance(Position3D.of(1, 1, 1)),
+            3,
+        )
+
+    def test_manhattan_distance_to_origin(self):
+        self.assertEqual(
+            Position3D.of(2, 2, 2).manhattan_distance_to_origin(), 6
+        )
+        self.assertEqual(
+            Position3D.of(5, -3, 2).manhattan_distance_to_origin(), 10
+        )