52 lines
1.4 KiB
Python
52 lines
1.4 KiB
Python
# -*- encoding: utf-8 -*-
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import sys
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import numpy as np
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import parse
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from docplex.mp.model import Model
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lines = sys.stdin.read().splitlines()
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sensor_to_beacon: dict[tuple[int, int], tuple[int, int]] = {}
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for line in lines:
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r = parse.parse(
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"Sensor at x={sx}, y={sy}: closest beacon is at x={bx}, y={by}", line
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)
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sensor_to_beacon[int(r["sx"]), int(r["sy"])] = (int(r["bx"]), int(r["by"]))
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xy_max = 4_000_000 if max(sensor_to_beacon) > (1_000, 0) else 20
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row = 2_000_000 if max(sensor_to_beacon) > (1_000, 0) else 10
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no_beacons_row_l: list[np.ndarray] = []
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for (sx, sy), (bx, by) in sensor_to_beacon.items():
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d = abs(sx - bx) + abs(sy - by) # closest
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no_beacons_row_l.append(sx - np.arange(0, d - abs(sy - row) + 1))
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no_beacons_row_l.append(sx + np.arange(0, d - abs(sy - row) + 1))
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beacons_at_row = set(bx for (bx, by) in sensor_to_beacon.values() if by == row)
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no_beacons_row = set(np.concatenate(no_beacons_row_l)).difference(beacons_at_row)
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print(f"answer 1 is {len(no_beacons_row)}")
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# === part 2 ===
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m = Model()
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x, y = m.continuous_var_list(2, ub=xy_max, name=["x", "y"])
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for (sx, sy), (bx, by) in sensor_to_beacon.items():
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d = abs(sx - bx) + abs(sy - by)
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m.add_constraint(m.abs(x - sx) + m.abs(y - sy) >= d + 1, ctname=f"ct_{sx}_{sy}")
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m.set_objective("min", x + y)
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s = m.solve()
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# 10621647166538
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answer_2 = 4_000_000 * int(s.get_value(x)) + int(s.get_value(y))
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print(f"answer 2 is {answer_2}")
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