思路:
我的思路就是最简单的逆转. 这里有个大神版本的分治法https://discuss.leetcode.com/topic/9811/o-1-bit-operation-c-solution-8ms.
uint32_t reverseBits(uint32_t n) {
uint32_t res = 0;
for (int i = 0; i < 31; i++) {
res += (n & 1);
n >>= 1;
res <<= 1;
}
res += (n & 1);
return res;
}