程序代码：

#include <stdio.h>
#include <math.h>

unsigned int rev1(unsigned int x)
{
    return x ^ (1 << (int)(log(x + 0.9) / log(2.0) + 0.1) + 1) - 1;
}

int main()
{    
    printf("%u\n",rev1(3456));
    return 0;
}