My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Update 2018/10 solution
+37
-45
+37
-45
2018/day10.py
+37
-45
2018/day10.py
···
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import fileinput
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from copy import deepcopy
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from itertools import count
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from utils import parse_nums
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INF = 1e9
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POINTS = []
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for line in fileinput.input():
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x, y, dx, dy = parse_nums(line)
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POINTS.append([x, y, dx, dy])
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def simulate(points, seconds=None):
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best_x = INF
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best_y = INF
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best_x = INF
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best_y = INF
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seconds = 0
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if seconds:
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loop = range(seconds)
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else:
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loop = count()
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for tick in loop:
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min_x = INF
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max_x = -INF
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min_y = INF
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max_y = -INF
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for i, (x, y, dx, dy) in enumerate(points):
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min_x = min(min_x, x)
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max_x = max(max_x, x)
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min_y = min(min_y, y)
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max_y = max(max_y, y)
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points[i][0] += dx
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points[i][1] += dy
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diff_x = max_x - min_x
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diff_y = max_y - min_y
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while True:
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min_x = INF
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max_x = -INF
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min_y = INF
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max_y = -INF
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improved = False
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for i, (x, y, dx, dy) in enumerate(POINTS):
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min_x = min(min_x, x)
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max_x = max(max_x, x)
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min_y = min(min_y, y)
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max_y = max(max_y, y)
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if diff_x < best_x:
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best_x = diff_x
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improved = True
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if diff_y < best_y:
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best_y = diff_y
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improved = True
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POINTS[i][0] += dx
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POINTS[i][1] += dy
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if not improved:
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return tick - 1
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diff_x = max_x - min_x
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diff_y = max_y - min_y
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improved = False
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POINTS = []
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if diff_x < best_x:
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best_x = diff_x
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improved = True
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if diff_y < best_y:
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best_y = diff_y
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improved = True
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for line in fileinput.input():
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x, y, dx, dy = parse_nums(line)
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POINTS.append([x, y, dx, dy])
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if not improved:
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break
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seconds += 1
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points = deepcopy(POINTS)
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seconds_to_message = simulate(points)
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simulate(POINTS, seconds=seconds_to_message)
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# Reverse by 2 timesteps to reassemble message
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for i, (x, y, dx, dy) in enumerate(POINTS):
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POINTS[i][0] -= dx * 2
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POINTS[i][1] -= dy * 2
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points = {(x, y) for x, y, dx, dy in POINTS}
···
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for y in range(min_y, max_y + 1):
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print ''.join('#' if (x, y) in points else '.' for x in range(min_x, max_x + 1))
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print "Seconds until the above message is formed:", seconds_to_message
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print "Seconds until the above message is formed:", seconds - 1