Method pop

S-Stack/StacksUsingQueue.cpp:83–100

pop expensive

	//pop expensive
    void pop(){
        if(q1.empty()){
            cout << "Stack is empty!" << endl;
            return ;
        }
        
        while(q1.size() != 1){
            q2.push(q1.front());
            q1.pop();
        }

        q1.pop();
        N--;

        queue<int> temp = q1;
        q1 = q2;
        q2 = temp;    
    }

    int top(){
        if(q1.empty()){