UVa 11111 Generalized Matrioshkas

UVa 11111 Generalized Matrioshkas

算法并不难，是需要用到栈就行了，一个元素记录两个值：自身的大小和剩余的容量。
当遇到一个负数的时候，如果当前栈顶元素可以容纳，直接压入栈中，否则则失败；
当遇到一个正数的时候，和栈顶元素比较，相加为0的话，弹出栈顶元素，同时修改当前栈顶元素的剩余容量，相加不为0，则失败。
注意：最终如果成功的话，栈应该为空。
以下是我的代码：

#include < iostream >
#include < sstream >
#include < string >
#include < stack >
#include < cstdio >
using   namespace  std;

struct  Type
{
    Type( const   int   & a, const   int   & b):size_(a),capacity_(b) {}
     int  size_,capacity_;
};

int  main()
{
     /*
    freopen("data.in","r",stdin);
    freopen("data.out","w",stdout);
    // */

     string  line;
     while (getline(cin,line))
    {
        istringstream sin(line);
        stack < Type >  s;
         bool  success( true );
         int  t;
         while (sin >> t)
        {
             if (t < 0 )
            {
                 if (s.empty())
                    s.push(Type(t,t));
                 else
                {
                     if (s.top().capacity_ < t)
                        s.push(Type(t,t));
                     else
                    {
                        success = false ;
                         break ;
                    }
                }
            }
             else
            {
                 if (s.empty())
                {
                    success = false ;
                     break ;
                }
                 else
                {
                     if (s.top().size_ + t != 0 )
                    {
                        success = false ;
                         break ;
                    }
                     else
                    {
                        s.pop();
                         if ( ! s.empty())
                            s.top().capacity_ += t;
                    }
                }
            }
             /*
            stack<Type> st(s);
            while(!st.empty())
            {
                cout<<st.top().size_<<" "<<st.top().capacity_<<endl;
                st.pop();
            }
            cout<<endl;
            // */
        }

         if (success  &&  s.empty())
            cout << " :-) Matrioshka! " << endl;
         else
            cout << " :-( Try again. " << endl;
    }

     return   0 ;
}