用栈做逆波兰式表达式的计算,为什么没结果输出?解决思路

用栈做逆波兰式表达式的计算,为什么没结果输出?
#include   <iostream>
#include   <cassert>
#include   <cmath>

using   namespace   std;

class   Stack;

class   StackNode
{
friend   class   Stack;
private:
double   data;
StackNode*   link;
StackNode(double   d=0.0,   StackNode*   l=NULL):data(d),link(l){}
};

class   Stack
{
private:
StackNode*   top;
public:
Stack():top(NULL){}
~Stack();
void   Push(const   double&   item);
double   Pop();
double   GetTop();
void   MakeEmpty();
bool   IsEmpty()   const   {return   top   ==   NULL;}

};

Stack::~Stack()
{
StackNode*   p;
while   (top   !=   NULL)
{
p   =   top;
top   =   top-> link;
delete   p;
}

}

void   Stack::MakeEmpty()
{
StackNode*   p;
while   (top   !=   NULL)
{
p   =   top;
top   =   top-> link;
delete   p;
}
}

void   Stack::Push(const   double&   item)
{
top   =   new   StackNode(item,top);
}

double   Stack::Pop()
{
assert(!IsEmpty());
StackNode*   p   =   top;
double   retvalue   =   p-> data;
top   =   top-> link;
delete   p;
return   retvalue;
}

double   Stack::GetTop()
{
assert(!IsEmpty());
return   top-> data;
}

class   Calculator
{
private:
void   AddOperand(double   value);                   //进操作数栈
bool   Get2Operands(double&   left,   double&   right);
void   DoOperator(char   op);
Stack   s;
public:
CalCulator();
void   Run();
void   Clear();
};

int   main()
{
Calculator   a;
a.Run();
return   EXIT_SUCCESS;
}

void   Calculator::AddOperand(double   value)
{
s.Push(value);
}

bool   Calculator::Get2Operands(double&   left,   double&   right)
{
if   (s.IsEmpty())
{
cerr < < "操作数不存在! " < <endl;
Clear();
return   false;
}

right   =   s.Pop();

if   (s.IsEmpty())
{
cerr < < "操作数不存在! " < <endl;
Clear();
return   false;
}

left   =   s.Pop();

return   true;
}

void   Calculator::DoOperator(char   op)
{
double   left   =   0,
      right   =   0;
bool   result   =   Get2Operands(left,right);

if   (result   ==   true)
{
switch(op)
{
case   '+ ':
s.Push(left+right);
break;
case   '- ':
s.Push(left-right);
break;
case   '/ ':
if   (right   ==   0.0)
{
cerr < < "除数不能为○! " < <endl;
Clear();
}
else
s.Push(left/right);
break;
case   '* ':

s.Push(left*right);
break;
case   '^ ':
s.Push(pow(left,right));
break;
}
}
else
Clear();
}

void   Calculator::Run()
{
char   ch;
double   newoperand;
while   (cin> > ch,ch!= '# ')
{
switch(ch)
{
case   '+ ':
case   '- ':
case   '* ':
case   '/ ':
DoOperator(ch);
break;
default:
cin.putback(ch);
cin> > newoperand;
AddOperand(newoperand);
break;
}
}
}

void   Calculator::Clear()
{
s.MakeEmpty();
}


程序编译通过了.可没结果出来..

[解决办法]
调试呀，单步跟踪。
[解决办法]
你一个输出都没有，怎么能要求有显示