30 lines
782 B
Python
30 lines
782 B
Python
def convex_hull(points):
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points = sorted(set(points))
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if len(points) <= 1:
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return points
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def hull(points):
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def cross(a, b, c):
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return (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0])
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res = []
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for p in points:
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while len(res) >= 2 and cross(res[-2], res[-1], p) >= 0:
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res.pop()
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res.append(p)
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return res
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return hull(points)[:-1] + hull(reversed(points))[:-1]
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def test():
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import random
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assert convex_hull([(0, 0), (0, 0)]) == [(0, 0)]
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assert convex_hull([(i // 10, i % 10) for i in range(100)]) == [(0, 0), (0, 9), (9, 9), (9, 0)]
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print(len(convex_hull([(random.randint(0, 10000), random.randint(0, 10000)) for i in range(10000)])))
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test()
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