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.
题解：很简单，一位一位的和1做"与"运算就好。
class Solution { public: int hammingWeight(uint32_t n) { int ans=0; while(n>0){ ans+=((n&1)==0?0:1); n>>=1; } return ans; } };
leetcode 191 Number of 1 Bits(位运算)
原文：http://www.cnblogs.com/zywscq/p/5218094.html