Leetcode 第190题 Reverse Bits

题目：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

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题目含义：

• 题目含义是将一个32位的二进制数，将对称的每一位对调，输出结果数

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思路：

• 本题考查位操作
• 将数组n与1进行与操作确定最后一位是1还是0
• 然后将结果数字res左移一位并加上n的最后一位
• 每个循环中都要讲数字n右移一位

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代码：

• C++：

class Solution {public:    uint32_t reverseBits(uint32_t n) {        uint32_t res=0;        for(int i=0;i<32;i++)        {            if(n & 1 ==1)//如果数字n的最后一位是1             {                res=(res<<1)+1;            }            else            {                res=res<<1;            }            n=n>>1;        }        return res;    }};