#include<iostream>

using namespace std;

template<typename T>
class Vector {

private:
    int size=0;
    int capacity=1;
    T* arr;
public:
    Vector(int size_array,T* a){
        size=size_array;
        capacity=size*2;
        arr=new T[capacity];
        for (int i = 0; i < size; ++i) {
            arr[i] = a[i];
        }
    
    }

    Vector(){
        arr= new T[capacity];
    }
    ~Vector(){
       delete[]arr;

    }
    

void push_back(T data){
    if (size==capacity){
        T*temp = new T[capacity*2];
        for (int i=0;i<size;i++){
            temp[i]=arr[i];
        }
        delete[]arr;
        arr=temp;
        capacity*=2;
    }
    arr[size]=data;
    // cout<<endl;
    size++;
}

void pop_back(){
    size-=1;
    T* temp= new T[capacity];
    for (int i;i<size;i++){
        temp[i]=arr[i];
    }
    delete[]arr;
    arr=temp;
}

T &get(int index){
    // cout<<" a ";
    return arr[index];
}

int get_size(){
    return size;
}

void resize(int new_size){
    T default_var;
    if (new_size<size){
    T* temp= new T[new_size];
    for (int i=0;i<new_size;i++){
        temp[i]=arr[i];
    }
    delete[]arr;
    arr=temp;
    }
    else{
    T* temp= new T[new_size];
    for (int i=0;i<new_size;i++){
        temp[i]=arr[i];
    }
    delete[]arr;
    arr=temp;
    }
    capacity=2*new_size;
    size=new_size;
}
/// 
int get_capacity(){

    return capacity;
}

T& operator[](int a){return arr[a];}

};
// template<typename T>
// std::ostream& operator<<(std::ostream& out , Vector<T > b)
// {
//      for (int i=0;i<b.get_size();i++){
//     out << b[i] <<",";
//     }
//     return out;
// }

int main(){
    int myarray[]={};
    Vector<int> vec = Vector<int> ();
    Vector<string> vec1 = Vector<string> ();
    cout<<endl;
    vec.push_back(1);
    vec.push_back(2);
    vec.push_back(3);
    vec[2]=4;
    // vec.push_back(4);
    // cout<<vec;
    for (int i=0;i<vec.get_size();i++){
    cout << vec[i] <<"  ";
    }
    // vec.pop_back();
    // for (int i=0;i<vec.get_size();i++){
    // cout << vec[i] <<"  ";
    // }
    // vec1.push_back("ali");
    // vec1.push_back("o");
    // for (int i=0;i<vec1.get_size();i++){
    // cout << vec1[i] <<"  ";
    // }
    // vec1.push_back("p");
    // vec1.push_back("hello");
    // // vec1.pop_back();
    // vec1.resize(8);
    // for (int i=0;i<vec1.get_size();i++){
    // cout << vec1[i] <<"  ";
    // }
    return 0;
}