ACM-392 Polynomial Showdown with C++

#include <iostream>
#include <sstream>
#include <list>


using namespace std;
string showExponentSP(int temp, int item); //用來處理輸入裡面最先出現的項次
string showExponent(int temp, int item);   //用來處理剩下的項次
//item 表示"項次"
//temp 表示"輸入的值"


int main()
{
    string str = "";
    list<int> l;

    int input;
    int counter = 0;
    int level = 8;

    cin>>input;

    while( cin )
    {
        l.push_back(input);
        counter++;

        if(counter == 9)
        {
            list<int>::iterator iter = l.begin();
            while( iter != l.end() ) {
                if(str.empty())
                {
                    str.append(showExponentSP(*iter,level));
                }
                else
                {
                    str.append(showExponent(*iter,level));
                }
                ++iter;
                level--;
            }

            cout<<str<<endl;
            str.clear();
            l.clear();
            counter = 0;
            level = 8;
        }
        cin>>input;
    }
    return 0;

}



string showExponentSP(int temp, int item)
{
    string s="";
    stringstream ss(s);

    if(item == 0)
    {
        ss<<temp;
    }
    else if(item == 1)
    {
        if (temp == 0)
        {
            ss<<"";
        }
        else
        {
            if(temp == -1)
            ss<<"-x";
            else if(temp == 1)
            ss<<"x";
            else
            ss<<temp<<"x";
        }
    }
    else
    {
        if (temp == 0)
        {
            ss<<"";
        }
        else
        {
            if(temp == -1)
            ss<<"-x^"<<item;
            else if(temp == 1)
            ss<<"x^"<<item;
            else
            ss<<temp<<"x^"<<item;
        }
    }
    return ss.str();
}


string showExponent(int temp, int item)
{
    string s="";
    stringstream ss(s);
    if(item>1)
    {
        if(temp == -1)
        ss<<" - "<<"x^"<<item;
        else if(temp == 1)
        ss<<" + "<<"x^"<<item;
        else if(temp<0)
        ss<<" - "<<(-temp)<<"x^"<<item;
        else if(temp>0)
        ss<<" + "<<temp<<"x^"<<item;
        else
        ss<<"";
    }
    else if(item == 0)
    {
        if(temp<0)
        ss<<" - "<<(-temp);
        else if(temp>0)
        ss<<" + "<<temp;
        else
        ss<<"";
    }else
    {
        if(temp == -1)
        ss<<" - "<<"x";
        else if(temp == 1)
        ss<<" + "<<"x";
        else if(temp<-1)
        ss<<" - "<<(-temp)<<"x";
        else if(temp>1)
        ss<<" + "<<temp<<"x";
        else
        ss<<"";
    }
    //cout<<item<<"  ";
    return ss.str();
}