Lista

//lista.hpp



#ifndef LISTA_DEF
#define LISTA_DEF
#include <stdlib.h>
#include <iostream>
using namespace std;

template <class T>

class List{
    private:
        struct listEl{

        T content;
        struct listEl *next;
        };
        int noEl;
        listEl *tail;
        listEl *head;
    public:
        List() {tail=NULL; head=NULL; noEl=0;}
        List(const List<T>&);
        virtual ~List();

        List<T>& operator=(const List<T>&);
        int getSize()const {return noEl;}
        void clear();

        bool empty()const{return head==NULL? 1:0;}
        bool add(int, const T&);
        bool remove(int);
        bool read(int, T&)const;
    };


template <class T>
   ostream& operator<<(ostream &out, const List<T> &ref){

       out<<"-------"<<endl;
       for(int i=1; i<=ref.getSize(); i++){
       out<<" ";
       T res; //npr int rezultat
       ref.read(i,res);//sa i-te pozicije ocitaj sadrzaj i upisi u res
       out<<res;
       } out<<"------";
       return out;


   }
       template <class T>
       List<T>:: List(const List<T> &ref){
           tail=NULL;
           head=NULL;
           noEl=0;
            for(int i=1; i<=ref.noEl; i++)
               {

                T res; //int element
                if(ref.read(i,res))
                add(i,res);}

        }

        template <class T>
        List<T>:: ~List(){
            while(!empty())
                    remove(1);
        }

        template <class T>
        List<T>& List<T>::operator=(const List<T> &ref){
            if(this!= &ref) {
                clear();
                tail=NULL;
                head=NULL;
                noEl=0;
                for(int i=1; i<ref.noEl; i++){
                    T res;
                    if(ref.read(i,res)) add(i,res);
                }


            }return *this;

        }

        template <class T>
        void List<T>::clear(){
            while(!empty()) remove(1);
        }

        template <class T>
        bool List<T>:: add(int n, const T &ref_value){
            bool isempty = empty(); //probaj i bez isempty

            if(n<1 || ( !isempty && n>noEl+1))
            return false;
                else
                {
                    listEl *newEl = new listEl;
                        if(newEl==NULL)
                        return false;
                    else {

                        newEl->content = ref_value;
                        if(n==1){
                        newEl->next = head;
                        head = newEl;
                        }
                        else if(n==noEl+1){

                        newEl->next = NULL;
                        tail->next = newEl;
                        }
                        else {
                        listEl *tmp = head;
                        for(int i=2; i<n; i++)
                        tmp = tmp->next;
                        newEl->next = tmp->next; //umesto =tmp.next probaj tmp
                        tmp->next = newEl;
                        }
                        noEl++;
                if(newEl->next==NULL) tail=newEl;
        return true;

                }
    }

}



        template <class T>
        bool List<T>:: remove(int n){
            if(empty() || n<1 || n>noEl) return false;

               else {
                if(n==1) {
                //kada se uklanja sa prve pozicije poenta je da se promeni adresa od head,
                //a zatim izvrsi brisanje
                listEl *tmp = head;
                head = head->next;
                delete tmp;
                noEl--;
                }
            else {
                listEl *tmp = head;
                for(int i=2; i<n; i++)
                tmp = tmp->next;
                listEl *del = tmp->next;
                tmp->next = del->next;
                if(tail==del)
                        tail = tmp;
                    delete del;
                noEl--;
            }
            return true;
            }
        }

        template <class T>
        bool List<T>:: read(int n, T& ref_value)const{
            if(empty() || n<1 || n>noEl) return false;
                else {
                    if(n==1) ref_value = head->content;
                    else
                    if(n==noEl) ref_value = tail->content;
                    else {
                    listEl *tmp = head;
                        for(int i=1; i<=n; i++)
                            tmp = tmp->next;
                            ref_value = tmp->content;
                        }return true;

                }

        }

#endif




//main.cpp




#include "lista.hpp"


int main(){

    List<int> list1;

    list1.clear();
cout<<"empty? "<<list1.empty()<<endl;


    list1.add(1,21);
    list1.add(2,24);
    cout<<list1<<endl;
    cout<<"size: "<<list1.getSize()<<endl;

cout<<"empty? "<<list1.empty()<<endl;




  //  if(list1.empty() )  cout<<"jeste"<<;
   // else
   // cout<<"nije"<<endl;


     //   cout<<list1<<endl;




return 0;
}