Reverse Bits

Reverse bits of a given 32 bits unsigned integer.
For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000).
Follow up:
If this function is called many times, how would you optimize it?
Related problem: Reverse Integer
Credits:

Special thanks to @ts for adding this problem and creating all test cases.

代码：

class Solution {public:    uint32_t reverseBits(uint32_t n) {        unsigned int result = 0;for (int i = 0; i < 32; i++) {result <<= 1;result |= (n & 1);n >>= 1;}return result;    }};