Checking for powers of two source codeThis snippet submitted by Webmaster on 2005-01-26. It has been viewed 26502 times.Rating of 6.4 with 266 votes /* The following code uses bitwise operators to determine
if an unsigned integer, x, is a power of two. If x is a power of two, x is represented in binary
with only a single bit; therefore, subtraction by one removes that bit and flips all the
lower-order bits. The bitwise and <http://www.cprogramming.com/tutorial/bitwise.html>
then effectively checks to see if any bit is the
same. If not, then it's a power of two.*/
int powerOfTwo(unsigned int x)
{
return !((x-1) & x);
}
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