【leetcode】Reverse Bits（middle）

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000).

思路：

n一直右移， ans一直左移。

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        uint32_t ans = 0;
        for(int i = 0; i < 32; i++)
        {
            if(n & 0x0001 == 1)
            {
                n = n >> 1;
                ans = ans << 1;
                ans |= 0x0001;
            }
            else
            {
                n = n >> 1;
                ans = ans << 1;
            }
        }
        return ans;
    }
};

大神总会有更简单的写法：

     uint32_t  reverseBits(uint32_t n) {
        uint32_t result= 0;
        for(int i=0; i<32; i++)
            result = (result<<1) + (n>>i &1);

        return result;
    }