中缀表达式转后缀表达式

/*************************************************************************
    > File Name: Stack.cpp
    > Author:keson
    > Mail:[email protected]
    > Created Time: 2014年11月21日 星期五 18时57分02秒
 ************************************************************************/

#include<iostream>
#include<vector>
#include"Stack.h"
using namespace std;
vector<char> output;
Stack<char> buffer(100);

void InfixToPostfix(const string &s)

{
    for(int i=0;i<s.size();i++)
    {
        if(s[i]!='+'&&s[i]!='*'&&s[i]!='('&&s[i]!=')')
            output.push_back(s[i]);
        else
        {
           if(buffer.Empty())
               buffer.push(s[i]);
           else
             {
              switch(s[i])
              {
                  case '+':
                       while(!buffer.Empty())
                       {
                            if(buffer.back()=='(')
                                break;
                            else
                              {
                                char c=buffer.pop();
                                output.push_back(c);
                              }
                        }
                        buffer.push('+');
                        break;
                    case '*':
                               buffer.push('*');break;
                    case '(':
                               buffer.push('(');break;
                    case ')':
                             while(buffer.back()!='(')
                             {
                                 char c=buffer.pop();
                                 output.push_back(c);
                             }
                             buffer.pop(); //pop出’（‘
                              break;
                    default:break;
                    }
            }
       }
}
while(!buffer.Empty())
{ char c=buffer.pop();
   output.push_back(c);
}
}

int main()
{

 string s("a+b*c+(d*e+f)*g");
 InfixToPostfix(s);
 for(auto c:output)
   cout<<c<<" ";
   cout<<endl;


}