/in/foo.cc:13:18: error: expected unqualified-id before 'int'
     int coe[100],int index[100];
                  ^~~
/in/foo.cc: In constructor 'PolyListNode::PolyListNode()':
/in/foo.cc:18:17: error: 'index' was not declared in this scope
    cin>>coe[i]>>index[i];
                 ^~~~~
/in/foo.cc: In member function 'int PolyListNode::sum()':
/in/foo.cc:25:22: error: 'index' was not declared in this scope
    s+=coe[i]*power(x,index[i]);
                      ^~~~~