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?
这个问题就是一个数字移位和赋值的问题,每次取出源操作数的最低位赋给目标操作数,并且源操作数右移一位,目标操作数左移一位。
class Solution {
public:
uint32_t reverseBits(uint32_t n)
{
uint32_t iRet = 0;
uint32_t iRes = n;
for(int i = 0; i != 32; ++i)
{
iRet <<= 1;
iRet = iRet | iRes & 1;
iRes >>= 1;
}
return iRet;
}
};
学习了c++的移位运算,c++还是弱的不行,慢慢学,不放弃,总会有改变的!!!
原文:http://www.cnblogs.com/bestwangjie/p/4338429.html