void printbinary(const int val) //由
{
unsigned int i = 1;
i = i << (sizeof(i)*8 - 1) //拿到unsigned类型的位数,左移(位数-1)位达到最左边一位为1,然后进for循环判断
while(i)
{
if(val & i)
cout << "1";
else
cout << "0";
i = i >> 1;
}
}