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f93cce66a6
* some pytest on math folder * Run the test function via a doctest Also format the code with psf/black as discussed in CONTRIBUTING.md * Update abs.py * Update average_mean.py
39 lines
1.4 KiB
Python
39 lines
1.4 KiB
Python
from typing import Tuple, List
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def n31(a: int) -> Tuple[List[int], int]:
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"""
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Returns the Collatz sequence and its length of any postiver integer.
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>>> n31(4)
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([4, 2, 1], 3)
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"""
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if not isinstance(a, int):
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raise TypeError("Must be int, not {0}".format(type(a).__name__))
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if a < 1:
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raise ValueError("Given integer must be greater than 1, not {0}".format(a))
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path = [a]
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while a != 1:
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if a % 2 == 0:
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a = a // 2
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else:
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a = 3 * a + 1
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path += [a]
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return path, len(path)
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def test_n31():
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"""
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>>> test_n31()
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"""
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assert n31(4) == ([4, 2, 1], 3)
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assert n31(11) == ([11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1], 15)
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assert n31(31) == ([31, 94, 47, 142, 71, 214, 107, 322, 161, 484, 242, 121, 364, 182, 91, 274, 137, 412, 206, 103, 310, 155, 466, 233, 700, 350, 175, 526, 263, 790, 395, 1186, 593, 1780, 890, 445, 1336, 668, 334, 167, 502, 251, 754, 377, 1132, 566, 283, 850, 425, 1276, 638, 319, 958, 479, 1438, 719, 2158, 1079, 3238, 1619, 4858, 2429, 7288, 3644, 1822, 911, 2734, 1367, 4102, 2051, 6154, 3077, 9232, 4616, 2308, 1154, 577, 1732, 866, 433, 1300, 650, 325, 976, 488, 244, 122, 61, 184, 92, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1], 107)
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if __name__ == "__main__":
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num = 4
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path, length = n31(num)
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print(f"The Collatz sequence of {num} took {length} steps. \nPath: {path}")
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