【leetcode】Reverse Bits

题目描述

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?

解题思路：

就是每次放一个位上去，下面的代码主要是通过对1的移位判断有当前机器上无整型数有多少位

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        decltype(n) result = 0;
        int count = 0;
        for(decltype(n) i =1; i!=0;i<<=1){
            cout<<i<<endl;
            result = (result<<1)+(n>>count &1);
            count ++;
        }
        return result;
    }
};

PS：另外有一种用merge的方法做的O(n)复杂度的方法