On Sun, Dec 04, 2005 at 03:21:47PM +0300, Anton Nikiforov wrote: > Martijn van Oosterhout wrote: > >Let i be your input. > >Calculate t = -i. > >If i is in the right format, t will have exactly one bit set. > >Test this with t <> 0 and (t & i) == t > >If that's ok, then your answer is 32 - log2(t) > > > >Have a nice day, > Sorry, did not quite catch. > t in this case is int, and there is no log2(int) function..... But there is a log(x,y) function, so log(2,t) would work also. Note that 255.255.255.0 stored as integer is -256. Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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