題目

Reverse bits of a given 32 bits unsigned integer.

Example:

Input: 43261596
Output: 964176192
Explanation: 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?

思路

從右向左遇到1就加1，每次迴圈結果右移一位，直到遍歷32位，返回最終結果。

程式碼

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