一个同名变量定义在三个作用域中，怎么访问？
#include <iostream>
using namespace std;
int i = 0 ;
int main()
{
int i =1;
cout << "sec i = " << i << endl;
cout << "fst i = " << ::i << endl;
{
int i=2;
cout << endl << endl;
cout << "the i = " << i << endl;
cout << "sec i = " << ？？？:i << endl;
cout << "fst i = " << ::i << endl;
}
return 0;
}
