23dfcca431 2011-02-23        kinaba: int bitcnt(LL x)
23dfcca431 2011-02-23        kinaba: {
23dfcca431 2011-02-23        kinaba: 	int c = 0;
23dfcca431 2011-02-23        kinaba: 	for(; x; x>>=1)
23dfcca431 2011-02-23        kinaba: 		c += x&1;
23dfcca431 2011-02-23        kinaba: 	return c;
23dfcca431 2011-02-23        kinaba: }