Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of ’1‘ bits it has (also known as the Hamming weight).

For example, the 32-bit integer ’11‘ has binary representation 00000000000000000000000000001011, so the function should return 3.

#include<iostream>
#include<vector>
using namespace std;

typedef unsigned __int32 uint32_t;

int hammingWeight(uint32_t n) {

	int count = 0;
	while (n)
	{
		++count;
		n = n&(n-1);
	}
	return count;
}

Number of 1 Bits

原文：http://blog.csdn.net/li_chihang/article/details/44620087