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 Select a Forum     Round Tables New Member Discussions News Discussions Algorithm Matches Marathon Matches NASA Tournament Lab TopCoder Cookbook High School Matches Sponsor Discussions Development Forums Design Forums Search | Watch Thread  |  My Post History  |  My Watches  |  User Settings View: Flat (newest first)  | Threaded  | Tree Previous Thread  |  Next Thread Forums Tutorial Discussions A bit of fun: fun with bits Checking if a number is a power of two << PREV    [ 1 2 ]
 Re: Checking if a number is a power of two (response to post by Kawigi) | Reply Isn't adding 1 after inverting the same as subtracting one before inverting?Doh! Of course is it. Please ignore my claim that i & -i tells you whether i is one less than a power of 2.
 Re: Checking if a number is a power of two (response to post by kyky) | Reply It is also possible to iterate over all the subsets of a particular subset (represented by a bit pattern), provided that you don't mind visiting them in reverse order (if this is problematic, put them in a list as they're generated, then walk the list backwards).Why not just use (superset - i) instead of i wherever you need the subset, if you need them in increasing order?
 Re: Checking if a number is a power of two (response to post by dskloet) | Reply i would like bitset to have +, -, *, / operators, they would help a lot :(.Is there a way to know if there is carry without using assembler???
 Re: Checking if a number is a power of two (response to post by dskloet) | Reply Neat idea, as a slight improvement I would go for (superset ^ i) here, same output, different instruction ;) [just one bitwise operation, no arithmetics done]
 Re: Checking if a number is a power of two (response to post by rserranop) | Reply Is there a way to know if there is carry without using assembler???If a and b are unsigned ints, then a + b will overflow if```a > UINT_MAX - b ```Of course, assembler will be faster.
 Re: Checking if a number is a power of two (response to post by kyky) | Reply Would someone please tell me help to prove x&(x-1) ?How to deal with x -1 ? I don't know to to use Demorgan and Distributive property over that.Many thanks.
 Forums Tutorial Discussions A bit of fun: fun with bits Checking if a number is a power of two Previous Thread  |  Next Thread << PREV    [ 1 2 ]