0%

# Reverse Bits

Posted on 2015-03-11 Edited on 2020-01-12 In leetcode Views: Views: Disqus:

### 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?

### code

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11

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

Related Posts

- binary-watch
- 34_Search_for_a_Range
- summary-ranges-228
- leetcode no.3
- Number of 1 Bits

请我喝杯咖啡

WeChat Pay

Alipay

- Post author: Nicksxs
- Post link: https://nicksxs.me/2015/03/11/Reverse-Bits/
- Copyright Notice: All articles in this blog are licensed under BY-NC-SA unless stating additionally.