My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Update day10.py
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2019/day10.py
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2019/day10.py
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import fileinput
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from collections import deque, defaultdict
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def dist(x, y):
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return (((x[0] - y[0]) ** 2) + ((x[1] - y[1]) ** 2)) ** 0.5
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def angle(a, b):
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return math.atan2(a[1] - b[1], a[0] - b[0])
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from utils import Point
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# Read problem input
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for y, line in enumerate(fileinput.input()):
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for x, c in enumerate(line.strip()):
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if c == '#':
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asteroids.add((x, y))
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asteroids.add(Point(x, y))
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# Part 1
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detections = {
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ast: len(set(angle(ast, other) for other in (asteroids - set(ast))))
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for ast in asteroids
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a: len(set(a.angle(o) for o in (asteroids - set([a]))))
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for a in asteroids
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}
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station, num = max(detections.items(), key=lambda x: x[1])
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# the station (going from furthest to closest). We rotate in the
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# positive-radian direction as a hack, since the y-axis coordinates
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# actually increase going downwards (as opposed to upwards).
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by_angles = defaultdict(list)
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by_angle = defaultdict(list)
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for a in asteroids:
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by_angles[angle(station, a)].append(a)
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by_angle[station.angle(a)].append(a)
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for k, v in by_angles.items():
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v.sort(key=lambda a: -dist(station, a))
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for k, v in by_angle.items():
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v.sort(key=station.dist, reverse=True)
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queue = deque(sorted(by_angles.items()))
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queue = deque(sorted(by_angle.items()))
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# Rotate the queue to the starting angle
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start = math.pi / 2
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else:
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queue.rotate(-1)
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print "200th asteroid checksum:", vaporized[0] * 100 + vaporized[1]
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print "200th asteroid checksum:", vaporized.x * 100 + vaporized.y