очередь

#include "exception.cpp"
#include <iostream>
#include <fstream>

using namespace std;

template <class X>
class List
{
        struct Element
        {
                X inf;
                Element *next;
                Element (X x): inf(x), next(0)
                {
                }
        };
        Element *head;
        int size;
        Element *Find( int index)
        {
                if(index < 1||index > size)
                        return NULL;
                else
                {
                        Element *cur = head;
                        for(int i = 1; i < index; i++)
                                cur = cur->next;
                        return cur;
                }
        }
public:
        List():head(0), size(0)
        {
        }
        ~List()
        {
                while(!Empty())
                        Remove(1);
        }
        bool Empty()
        {
                return head == 0;
        }
        int GetLength()
        {
                return size;
        }
        X Get(int index)
        {
                if (index < 1 || index > size)
                {
                        throw ListException("ListException: get - list error");
                }
                else
                {
                        Element *r = Find(index);
                        X i = r->inf;
                        return i;
                }
        }
        void Insert(X data, int index)
        {
                if (index < 1 || index > size + 1)
                {
                        throw ListException("ListException: get - list error");
                }
                else
                {
                        Element *newPtr = new Element(data);
                        size = GetLength() + 1;
                        if (index == 1)
                        {
                                newPtr->next = head;
                                head = newPtr;
                        }
                        else
                        {
                                Element *prev = Find(index - 1);
                                newPtr->next = prev->next;
                                prev->next = newPtr;
                        }
                }
        }
        void Remove (int index)
        {
                if (index < 1 || index > size)
                {
                        throw ListException("ListException: get - list error");
                }
                else
                {
                        Element *cur;
                        --size;
                        if (index == 1)
                        {
                                cur = head;
                                head = head->next;
                        }
                        else
                        {
                                Element * prev = Find(index - 1);
                                cur = prev->next;
                                prev->next = cur->next;
                        }
                        cur->next = NULL;
                        delete cur;
                }
        }
        void Change ()
        {
                //Element *cur = head;
                for(Element *cur = head; cur != NULL; cur = cur -> next)
                {
                        if((cur->inf) % 2 == 0)
                                cur->inf = (cur -> inf)*2;
                }
        }
        void Print(ofstream &out)
        {
                for(Element * cur = head; cur != NULL; cur = cur->next)
                        out << cur->inf << " ";
                out << endl;
        }

};

int main()
{
        List <int> t;
        int i;
        ifstream in ("input.txt");
        ofstream out ("output.txt");
        while (in >> i)
                t.Insert(i, t.GetLength()+1);
        in.close();
        t.Change();
        t.Print(out);
        t.~List();
        out.close();
        return 0;
}