关于c++ primer中适配器的问题
#include <iostream>
#include <string>
#include <stack>
using namespace std;
int main()
{
stack<char> sexp;
string exp;
cout<<"Enter a expression:"<<endl;
cin>>exp;
string::iterator iter=exp.begin();
while(iter!=exp.end())
{
if(*iter!=')')
sexp.push(*iter);
else
{
while(sexp.top()!='('&&!sexp.empty())
{
sexp.pop();
}
if(sexp.empty())
cout<<"parentheses are not matched"<<endl;
else
{
sexp.pop();
sexp.push('@');
}
}
++iter;
}
return 0;
}
