c++ 64位二进制 移位运算并输出结果

一个很一般的程序

#include<iostream>

using namespace std;

void main(){

int a,b,p;

cout<<"entre a,b:"<<endl;

cin>>hex>>a>>b;

cout<<"a=";

cout.width(8); //宽度是8

cout.fill('0');//前面补0

cout <<hex << a<<endl;

cout<<"b=";

cout << hex << b<<endl;

p=b&0X80000000;

//cout << hex << p<<endl;

//cout << dec << p<< endl;

//cout<<p<<endl;

cout<<"after left shift a b=";

if(p==0){

a=a<<1;

b=b<<1;

    cout.width(8);

    cout.fill('0');

        cout<<a<<" ";

cout<<b<<endl;

}

else{

a=a<<1;

a=a|1;

b=b<<1;

        cout.width(8);

    cout.fill('0');

        cout<<a<<" ";

cout<<b<<endl;

}

}