23 lines
838 B
Python
23 lines
838 B
Python
def sign(n):
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return 0 if n == 0 else n // abs(n)
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def simulate_rope(input, segments):
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knots = [(0, 0)] * segments
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trail = {(0, 0)}
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for line in input.splitlines():
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direction, amount = line.split()
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hdx, hdy = {"L": (-1, 0), "R": (1, 0), "D": (0, -1), "U": (0, 1)}[direction]
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for _ in range(int(amount)):
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knots[0] = knots[0][0] + hdx, knots[0][1] + hdy
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for i in range(1, len(knots)):
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dx, dy = knots[i - 1][0] - knots[i][0], knots[i - 1][1] - knots[i][1]
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if abs(dx) > 1 or abs(dy) > 1:
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knots[i] = knots[i][0] + sign(dx), knots[i][1] + sign(dy)
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trail.add(knots[-1])
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return len(trail)
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def solve(inputstr):
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print(f"Part 1: {simulate_rope(inputstr, 2)}")
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print(f"Part 2: {simulate_rope(inputstr, 10)}")
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