HappyLeetcode58:Reverse Bits

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Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000).

Follow up:
If this function is called many times, how would you optimize it?

Related problem: Reverse Integer

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

这道题的难度不大，主要是位运算。因为是无符号数，所以我可以放心的让原数据右移，新数据得到新的一位之后进行左移。最终得到结果。对与有符号数，方法亦然。

代码如下：

class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        uint32_t result = 0;
        int bit;
        for (int i = 0; i < 32; ++i)
        {
            bit = n & 0x01;
            n >>= 1;
            result <<= 1;
            result = result | bit;
        }
        return result;
    }
};

值得一提的是， >>=和<<=这两个符号之前基本上就没有用过，所以第一次写代码的时候漏掉了=号，今后注意。

HappyLeetcode58:Reverse Bits

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原文地址：http://www.cnblogs.com/chengxuyuanxiaowang/p/4323355.html