指针的内存布局

#include<iostream>
using namespace std;
int main()
{
const int a=5;
int b=9;
const int* pa=&a;
int *const pb=&b;
cout<<"a的值是"<<*pa<<endl;
cout<<"a的地址是"<<pa<<endl;
cout<<"b的值是"<<*pb<<endl;
cout<<"b的地址是"<<pb<<endl; 
pa=&b;
//*pa=b;error
cout<<"*pa的值是"<<*pa<<endl;
cout<<"pa所指向的地址是"<<pa<<endl;
*pb=a;
//pb=&a;error
cout<<"*pb的值是"<<*pa<<endl;
cout<<"pb所指向的地址是"<<pa<<endl;

cout<<"a的值是"<<a<<endl;
cout<<"b的值是"<<b<<endl;
}