190. 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

按位翻转输入的整数。

代码如下：

 1 class Solution { 2 public: 3     uint32_t reverseBits(uint32_t n) { 4         unsigned ret = 0; 5         unsigned pos1 = 1 << 31; 6         unsigned pos2 = 1; 7         while(pos1) 8         { 9             if(pos1 & n)10                 ret |= pos2;11             pos2 <<= 1;12             pos1 >>= 1;13         }14         return ret;15     }16 };

leetcode 190