LeetCode 190 Reverse Bits [classic] 思维

Reverse bits of a given 32 bits unsigned integer.

Input: n = 11111111111111111111111111111101
Output: 3221225471 (10111111111111111111111111111111)
Explanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10111111111111111111111111111111.

Solution

Solution Illustration

点击查看代码

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        
        n = ((n & 0xffff0000) >> 16) | ((n & 0x0000ffff) << 16);
        n = ((n & 0xff00ff00) >> 8) | ((n & 0x00ff00ff) << 8);
        n = ((n & 0xf0f0f0f0) >> 4) | ((n & 0x0f0f0f0f) << 4);
        n = ((n & 0xcccccccc) >> 2) | ((n & 0x33333333) << 2);
        n = ((n & 0xaaaaaaaa) >> 1) | ((n & 0x55555555) << 1);
        
        return n;
        
    }
};