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* Update power.py * Update divide_and_conquer/power.py --------- Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>
52 lines
1.1 KiB
Python
52 lines
1.1 KiB
Python
def actual_power(a: int, b: int):
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"""
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Function using divide and conquer to calculate a^b.
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It only works for integer a,b.
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:param a: The base of the power operation, an integer.
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:param b: The exponent of the power operation, a non-negative integer.
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:return: The result of a^b.
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Examples:
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>>> actual_power(3, 2)
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9
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>>> actual_power(5, 3)
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125
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>>> actual_power(2, 5)
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32
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>>> actual_power(7, 0)
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1
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"""
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if b == 0:
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return 1
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if (b % 2) == 0:
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return actual_power(a, int(b / 2)) * actual_power(a, int(b / 2))
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else:
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return a * actual_power(a, int(b / 2)) * actual_power(a, int(b / 2))
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def power(a: int, b: int) -> float:
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"""
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:param a: The base (integer).
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:param b: The exponent (integer).
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:return: The result of a^b, as a float for negative exponents.
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>>> power(4,6)
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4096
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>>> power(2,3)
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8
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>>> power(-2,3)
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-8
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>>> power(2,-3)
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0.125
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>>> power(-2,-3)
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-0.125
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"""
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if b < 0:
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return 1 / actual_power(a, b)
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return actual_power(a, b)
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if __name__ == "__main__":
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print(power(-2, -3))
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