[理解leetcode解法]190. Reverse Bits 数字翻转

190. Reverse Bits 数字翻转

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

解法如下

class Solution{ public:  uint32_t reverseBits(uint32_t n){   if (!n)return n;   int num=31;   uint32_t tmp=0;   while (n > 0){                        //1    tmp |= (n & 0x1) << num;    n >>= 1;    num--;   }   return tmp;  } };

//1: 先取出最后一位，然后左移31位 n右移一位 再取出最后一位，然后左移30位.........如此类推