190. Reverse Bits

Reverse bits of a given 32 bits unsigned integer.

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​​

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