Reverse Bits

问题描述：翻转二进制位。

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        uint32_t res=0;
        for (int i = 0; i < 32; ++i) {
            //得到最低位，然后将其左移到最终位，和res或等
            res |= ((n >> i) & 1) << (31 - i);
        }
        return res;
    }
};