190. Reverse Bits -- 按位反转

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?

class Solution {

public:

    uint32_t reverseBits(uint32_t n) {

        uint32_t ret=0;

        for(int i=0; i<32; i++) {

            ret = (ret*2) + (n & 0x1);

            n /=2 ;

        }

        return ret;

    }

};