#include <iostream>
#include <math.h>
template<class T>
class vec{
private:
    T* arr = nullptr;
    int size = 0;
    int capacity = 0;
public:
    vec(int _size_ = 0):size(_size_),capacity(_size_+20){
        if(size<0 ){
            std::cout << "Incorrect value in Cons(1)" << std::endl;

        }
        else
            arr = new T[capacity];
    }
    ~vec(){
        delete[] arr;
    }
    void push_back(T value){
        if(size == capacity){
            size++;
            capacity*=2;
            T* temp = new T[size];
                   for(int i=0;i<size-1;i++){
                       temp[i] = arr[i];
                   }
                   delete[] arr;
                   arr = new T[capacity];
                   for(int i=0;i<size-1;i++){
                      arr[i] = temp[i];
                   }
                   arr[size-1] = value;
                   delete[] temp;
        }else{
            size++;
            arr[size-1] = value;
        }
    }
    T& at(int n)const{
        return arr[n];
    }
    int getsize()const{
        return size;
    }
    int getcapacity()const{
        return capacity;
    }
    void resize(int n){
        if(n < capacity){
            capacity = n;
            size = n;
            T* temp = new T[capacity];
            for(int i=0;i<n;i++){
                temp[i] = arr[i];

            }
            delete[] arr;
            arr = new T[capacity];
            for(int i=0;i<n;i++){
                arr[i] = temp[i];
            }
            delete[] temp;
        }else if(n>capacity){
            capacity = n;
            T* temp = new T[size];
            for(int i=0;i<size;i++){
                temp[i] = arr[i];
            }
            delete[] arr;
            arr = new T[capacity];
            for(int i=0;i<size;i++){
                arr[i] = temp[i];
            }
            delete[] temp;
        }
    }
    void print()const{
        std::cout << "-------------------" << std::endl;
        for(int i=0;i<size;i++){
            std::cout << arr[i] << " ";
        }
        std::cout << std::endl;
    }
    void printBack() const {
        if(size == 0){
            std::cout <<"No elements in this vector" << std::endl;
        }else
        std::cout << arr[size-1] << std::endl;
    }
    void printFront() const {
        if(size == 0){
            std::cout << "No elements in this vector" << std::endl;
        }else
        std::cout << arr[0] << std::endl;
    }
    void erase(T value){
        if(size == 0){
            std::cout << "Cant erase from null-value array" << std::endl;
        }else{
            for(int i=0;i<size;i++){
               if(arr[i] != value){
                   continue;
               }
               else{
                for(int j=i;j<size-1;j++){
                    arr[j] = arr[j+1];
                }
                   size--;
                   return;
               }
            }
        }

    }
    void printcapacity()const{
        std::cout << capacity << std::endl;
    }
    void printsize()const{
        std::cout << size << std::endl;
    }
    void clear(){
        delete[] arr;
        capacity = 10;
        size = 0;
        arr = new T[capacity];

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

};

int main(){

}