leetcode[191]:Number of 1 Bits

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.

int hammingWeight(uint32_t n) {    int i,res;    res=0;    for(i=0;i<32;i++)    {       res += (n>>i) & 0x01;    }    return res;}

熟悉一下位操作。