template <class T>
class vector{
    private:
        int length;
        int curSize;
        T *a;
    public:
        vector(){
            length = 1;
            curSize = 0;
            a = new T[length];
        }

        vector(int x){
            length = x;
            curSize = 0;
            a = new T[length];
        }

        void print(){
            for(int i=0; i<this->length; ++i){
                cout<<this->a[i]<<" ";
            }
            cout <<"\n";
        }

        vector<T> operator=(const vector<T> &rhs){
            this->a = rhs.a;
            this->curSize = rhs.curSize;
            this->length = rhs.length;
            return *this;
        }

        int len(){
            return length;
        }

        int size(){
            return curSize;
        }

        void push_back(int x){
            if(curSize < length){
                a[curSize] = x;
                curSize++;
            }else{
                length++;
                T *b = new T[length];
                for(int i=0; i<length; ++i){
                    b[i] = a[i];
                }
                b[curSize] = x;
                curSize++;
                a = b;
                delete[] b;
            }
        }

        T operator[](int index){
            if( index < curSize){
                return a[index];
            }
        }

        vector<T> operator*=(T lmd){
            for(int i=0; i<this->size(); ++i){
                this->a[i]*=lmd;
            }
            return *this;
        }

        vector<T> operator/=(T lmd){
            for(int i=0; i<curSize; ++i){
                this->a[i]/=lmd;
            }
            return *this;
        }

        vector<T> operator+(const vector<T> &right){
            int n = this->curSize;
            int m = right.curSize;
            if(n == m){
                vector<T> b(n);
                for(int i=0; i<n; ++i){
                    b.a[i] = this->a[i] + right.a[i];
                }
                return b;
            }
        }

        vector<T> operator-(const vector<T> &right){
            int n = this->curSize;
            int m = right.curSize;
            if(n == m){
                vector<T> b(n);
                for(int i=0; i<n; ++i){
                    b.a[i] = this->a[i] - right.a[i];
                }
                return b;
            }
        }
};