See if a number is power of 2, then only one bit in the number will be set.
e.g. for 16, 00010000 assuming 8-bit representation.
then when you subtract 1 from this number, the bits to the right of the
previously set bit will be set, and the set bit will become unset.
e.g. 16 will become 15, 00001111.
Take bitwise and, th result will be 0 if it is a power of 2.
taking Logical NOT will give 1.
Hence the result.
Sanju
:)
On Sat, Aug 20, 2011 at 3:45 AM, SANDEEP CHUGH <sandeep.aa...@gmail.com>wrote:
> explain it plz
>
>
> On Sat, Aug 20, 2011 at 4:09 PM, Abhishek Yadav <
> algowithabhis...@gmail.com> wrote:
>
>> got it ...thanks
>>
>>
>> On Sat, Aug 20, 2011 at 4:04 PM, Sanjay Rajpal <srn...@gmail.com> wrote:
>>
>>> if(!(x & x-1)) printf("No. is power of 2");
>>>
>>>
>>> Sanju
>>> :)
>>>
>>>
>>>
>>> On Sat, Aug 20, 2011 at 3:32 AM, Abhishek Yadav <
>>> algowithabhis...@gmail.com> wrote:
>>>
>>>> Give a one-line C expression to test whether a number is a power of 2.
>>>>
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