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https://github.com/cupcakearmy/advent-of-code.git
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113 lines
3.1 KiB
Python
113 lines
3.1 KiB
Python
#!/usr/bin/env python
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from dataclasses import dataclass
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from os.path import dirname, join
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from typing import Literal
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# Day 09
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# Common
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def read_input(filename):
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data = join(dirname(__file__), '..', filename)
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with open(data) as f:
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return f.read().strip()
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test = read_input('test.txt')
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data = read_input('input.txt')
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@dataclass(unsafe_hash=True)
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class Point:
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x: int
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y: int
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def __add__(self, other: 'Point'):
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return Point(self.x + other.x, self.y + other.y)
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def __sub__(self, other: 'Point'):
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return Point(self.x - other.x, self.y - other.y)
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def distance(self, other: 'Point') -> int:
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return max(abs(self.x - other.x), abs(self.y-other.y))
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def normalise(self):
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self.x = max(-1, min(1, self.x))
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self.y = max(-1, min(1, self.y))
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return self
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Directions = Literal['U', 'D', 'L', 'R']
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Instruction = tuple[Directions, int]
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MAPPING: dict[Directions, Point] = {'U': Point(0, 1), 'D': Point(0, -1), 'L': Point(-1, 0), 'R': Point(1, 0)}
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class Rope:
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def __init__(self, instructions: list[Instruction], links: int) -> None:
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self.instructions = instructions
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start = Point(0, 0)
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self.touched: set[Point] = set([start])
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self.links = [start for _ in range(links)]
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def move(self, instruction: Instruction):
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direction, travel = instruction
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last = len(self.links) - 1
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for _ in range(travel):
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moved: list[Point] = []
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for i, link in enumerate(self.links):
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if i == 0:
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link = link + MAPPING[direction]
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else:
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head = moved[i-1]
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distance = head.distance(link)
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if distance > 1:
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link = link + (head - link).normalise()
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moved.append(link)
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if i == last:
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self.touched.add(link)
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self.links = moved
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def run(self):
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for instruction in self.instructions:
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self.move(instruction)
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return len(self.touched)
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@staticmethod
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def visualise(points: list[Point], numbered=True) -> str:
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"""
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Only used to visualise, not actual logic
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"""
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max_x = max(p.x for p in points)
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min_x = min(p.x for p in points)
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max_y = max(p.y for p in points)
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min_y = min(p.y for p in points)
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range_x = max_x - min_x
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range_y = max_y - min_y
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grid = [
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['.' for _ in range(range_x+1)]
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for _ in range(range_y+1)
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]
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for i, link in enumerate(points):
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row = grid[range_y-(link.y - min_y)]
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if row[link.x-min_x] == '.':
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row[link.x-min_x] = str(i) if numbered else "#"
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return '\n'.join(map(lambda line: ''.join(line), grid))
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@staticmethod
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def parse(data: str, links: int):
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instructions = [
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(i[0], int(i[1]))
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for i in map(lambda line: line.split(), data.splitlines())
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]
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return Rope(instructions, links)
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# Running
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grid = Rope.parse(data, 2)
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print(grid.run())
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grid = Rope.parse(data, 10)
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print(grid.run())
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