That’s the Hamming weight problem, a.k.a. population count. The link mentions efficient implementations. Quoting:
With unlimited memory, we could simply create a large lookup table of the Hamming weight of every 64 bit integer
That’s the Hamming weight problem, a.k.a. population count. The link mentions efficient implementations. Quoting:
With unlimited memory, we could simply create a large lookup table of the Hamming weight of every 64 bit integer