TheAlgorithms-Python

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"""
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https://en.wikipedia.org/wiki/Lucas_number
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"""
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def recursive_lucas_number(n_th_number: int) -> int:
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    """
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    Returns the nth lucas number
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    >>> recursive_lucas_number(1)
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    1
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    >>> recursive_lucas_number(20)
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    15127
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    >>> recursive_lucas_number(0)
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    2
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    >>> recursive_lucas_number(25)
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    167761
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    >>> recursive_lucas_number(-1.5)
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    Traceback (most recent call last):
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        ...
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    TypeError: recursive_lucas_number accepts only integer arguments.
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    """
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    if not isinstance(n_th_number, int):
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        raise TypeError("recursive_lucas_number accepts only integer arguments.")
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    if n_th_number == 0:
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        return 2
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    if n_th_number == 1:
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        return 1
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    return recursive_lucas_number(n_th_number - 1) + recursive_lucas_number(
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        n_th_number - 2
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    )
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def dynamic_lucas_number(n_th_number: int) -> int:
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    """
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    Returns the nth lucas number
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    >>> dynamic_lucas_number(1)
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    1
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    >>> dynamic_lucas_number(20)
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    15127
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    >>> dynamic_lucas_number(0)
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    2
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    >>> dynamic_lucas_number(25)
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    167761
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    >>> dynamic_lucas_number(-1.5)
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    Traceback (most recent call last):
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        ...
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    TypeError: dynamic_lucas_number accepts only integer arguments.
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    """
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    if not isinstance(n_th_number, int):
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        raise TypeError("dynamic_lucas_number accepts only integer arguments.")
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    a, b = 2, 1
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    for _ in range(n_th_number):
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        a, b = b, a + b
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    return a
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if __name__ == "__main__":
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    from doctest import testmod
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    testmod()
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    n = int(input("Enter the number of terms in lucas series:\n").strip())
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    print("Using recursive function to calculate lucas series:")
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    print(" ".join(str(recursive_lucas_number(i)) for i in range(n)))
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    print("\nUsing dynamic function to calculate lucas series:")
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    print(" ".join(str(dynamic_lucas_number(i)) for i in range(n)))
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