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Python Integer.is_perfect_square方法代码示例

本文整理汇总了Python中Cryptodome.Math.Numbers.Integer.is_perfect_square方法的典型用法代码示例。如果您正苦于以下问题:Python Integer.is_perfect_square方法的具体用法?Python Integer.is_perfect_square怎么用?Python Integer.is_perfect_square使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在Cryptodome.Math.Numbers.Integer的用法示例。


在下文中一共展示了Integer.is_perfect_square方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Python代码示例。

示例1: lucas_test

# 需要导入模块: from Cryptodome.Math.Numbers import Integer [as 别名]
# 或者: from Cryptodome.Math.Numbers.Integer import is_perfect_square [as 别名]
def lucas_test(candidate):
    """Perform a Lucas primality test on an integer.

    The test is specified in Section C.3.3 of `FIPS PUB 186-4`__.

    :Parameters:
      candidate : integer
        The number to test for primality.

    :Returns:
      ``Primality.COMPOSITE`` or ``Primality.PROBABLY_PRIME``.

    .. __: http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf
    """

    if not isinstance(candidate, Integer):
        candidate = Integer(candidate)

    # Step 1
    if candidate.is_even() or candidate.is_perfect_square():
        return COMPOSITE

    # Step 2
    def alternate():
        sgn = 1
        value = 5
        for x in xrange(10):
            yield sgn * value
            sgn, value = -sgn, value + 2

    for D in alternate():
        js = Integer.jacobi_symbol(D, candidate)
        if js == 0:
            return COMPOSITE
        if js == -1:
            break
    else:
        return COMPOSITE
    # Found D. P=1 and Q=(1-D)/4 (note that Q is guaranteed to be an integer)

    # Step 3
    # This is \delta(n) = n - jacobi(D/n)
    K = candidate + 1
    # Step 4
    r = K.size_in_bits() - 1
    # Step 5
    # U_1=1 and V_1=P
    U_i = Integer(1)
    V_i = Integer(1)
    U_temp = Integer(0)
    V_temp = Integer(0)
    # Step 6
    for i in xrange(r - 1, -1, -1):
        # Square
        # U_temp = U_i * V_i % candidate
        U_temp.set(U_i)
        U_temp *= V_i
        U_temp %= candidate
        # V_temp = (((V_i ** 2 + (U_i ** 2 * D)) * K) >> 1) % candidate
        V_temp.set(U_i)
        V_temp *= U_i
        V_temp *= D
        V_temp.multiply_accumulate(V_i, V_i)
        if V_temp.is_odd():
            V_temp += candidate
        V_temp >>= 1
        V_temp %= candidate
        # Multiply
        if K.get_bit(i):
            # U_i = (((U_temp + V_temp) * K) >> 1) % candidate
            U_i.set(U_temp)
            U_i += V_temp
            if U_i.is_odd():
                U_i += candidate
            U_i >>= 1
            U_i %= candidate
            # V_i = (((V_temp + U_temp * D) * K) >> 1) % candidate
            V_i.set(V_temp)
            V_i.multiply_accumulate(U_temp, D)
            if V_i.is_odd():
                V_i += candidate
            V_i >>= 1
            V_i %= candidate
        else:
            U_i.set(U_temp)
            V_i.set(V_temp)
    # Step 7
    if U_i == 0:
        return PROBABLY_PRIME
    return COMPOSITE
开发者ID:FndNur1Labs,项目名称:PokemonGo-DesktopMap,代码行数:92,代码来源:Primality.py


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