这是一段从别处拷来的一元多项式的代码，请大虾看一下

#include<iostream.h>
#include<list>
struct Term
{
float coef;
int exp_x,exp_y;
Term(float c,int e1,int e2){coef=c;exp_x=e1;exp_y=e2;}
Term(){}

friend int operator==(const Term & L,const Term & T)//项序比较，按x的升幂排列
{
return (L.exp_x==T.exp_x)&&(L.exp_y==T.exp_y);
}
friend int operator >(const Term & L,const Term & T)
{
return ((L.exp_x>T.exp_x)||(L.exp_x==T.exp_x)&&(L.exp_y>T.exp_y));

}
friend int operator <(const Term & L,const Term & T)
{
return ((L.exp_x<T.exp_x)||(L.exp_x==T.exp_x)&&(L.exp_y<T.exp_y));
}
friend Term & operator+=(Term & L,const Term & T)//幂指数对应相同，则系数相加
{
L.coef+=T.coef; return L;
}

friend istream & operator>>(istream & is,Term & T);
friend ostream & operator<<(ostream & os,const Term & T);
friend char compare(const Term & P,const Term & T);
friend Is_Empty(const Term & T){return !T.coef;}

};

char compare(const Term & P,const Term & T)
{
if(P==T) return'=';
else if(P<T) return '<';
else return'>';
}

istream & operator>>(istream & is,Term & T)
{
cout<<"Please input a coefficient!\n";
is>>T.coef;
cout<<"Please input the power of x!\n";
is>>T.exp_x;
cout<<"Please input the power of y!\n";
is>>T.exp_y;
return is;
}

ostream & operator<<(ostream & os,const Term & T)
{
if(T.coef>0) os<<'+';
os<<T.coef<<"x^"<<T.exp_x<<"y^"<<T.exp_y;
return os;
}

template<class ElemType>
class Polynomial
{
public:
Polynomial(const ElemType & P){Stop_flag=P;}
Polynomial(){}
~Polynomial(){}
Polynomial & operator=(const Polynomial & T);
Polynomial & operator+(const Polynomial & T);
friend istream & operator>>(istream & is,Polynomial<ElemType> & T);
friend ostream & operator<<(ostream & os,const Polynomial<ElemType> & T);
private:
List <ElemType> poly;//???????????????????????
//Term<T>*
ElemType Stop_flag;//用于判断多项式结束

};

template<class ElemType>
istream & operator>>(istream & is,Polynomial<ElemType> & T)
{
ElemType elem;
ListItr<ElemType>Itr(T.poly);
cout<<"Creat a Polynomial!\n";
cout<<"Please input coeffcient and power one by one!\n"
while(cin>>elem,!equal_stop(elem,T.Stop_lag)) Itr.Insert(elem);
return is;

}


编译的时候这样报错：
syntax error :missing ';' before '<'

请问：这是不是List引起的，或者应该怎么改动，
我对这一块C++的内容很不了解
谢谢了

辛苦了！

天哪，不知道为什么，我就是编译通不过，还是原来的样子
于是我把list那一行去掉，并且屏蔽掉下一段代码，加一个main，出现这样的报错：
LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
Debug/polynomial.exe : fatal error LNK1120: 1 unresolved externals
这是代码：
前面相同的省略了
template<class ElemType>
class Polynomial
{
public:
Polynomial(const ElemType & P){Stop_flag=P;}
Polynomial(){}
~Polynomial(){}
Polynomial & operator=(const Polynomial & T);
Polynomial & operator+(const Polynomial & T);
friend istream & operator>>(istream & is,Polynomial<ElemType> & T);
friend ostream & operator<<(ostream & os,const Polynomial<ElemType> & T);
private:
//list <ElemType> poly;
ElemType Stop_flag;//用于判断多项式结束

};
/*
template<class ElemType>
istream & operator>>(istream & is,Polynomial<ElemType> & T)
{
ElemType elem;
ListItr<ElemType>Itr(T.poly);
cout<<"Creat a Polynomial!\n";
cout<<"Please input coeffcient and power one by one!\n"
while(cin>>elem,!equal_stop(elem,T.Stop_lag)) Itr.Insert(elem);
return is;

}*/

int main()
{
int m=1;
return m;
}

或者是你的编译器的问题，我用Borland C++，没有问题。
看看是不是工程建错了