Mbpp/167

def next_power_of_2(n: int) -> int:
    """
    Returns the smallest power of 2 that is greater than or equal to n.
    Examples:
        next_power_of_2(0) -> 1
        next_power_of_2(3) -> 4
        next_power_of_2(16) -> 16
    """
    if n <= 1:
        return 1

    # Subtract 1 so that if n is already a power of 2 we keep it unchanged
    n -= 1

    # Propagate the highest set bit to all lower bits
    # We need to shift enough times to cover the bit length of n.
    # Since Python ints have arbitrary precision, we use a loop based on bit_length.
    shift = 1
    while shift < n.bit_length():
        n |= n >> shift
        shift <<= 1

    # Now n is of the form (2^k - 1). Adding 1 gives the next power of two.
    return n + 1

• 无失败测试

• 无失败测试