232.implement queue using stacks

class  {
    Stack<Integer> queue = new Stack<>();
    
    public () {
        
    }
    
    /** Push element x to the back of queue. */
    public void push(int x) {
        Stack<Integer> temp = new Stack<>();
        while(!queue.isEmpty())
            temp.push(queue.pop());
        queue.push(x);
        while(!temp.isEmpty())
            queue.push(temp.pop());
    }
    
    /** Removes the element from in front of queue and returns that element. */
    public int pop() {
        return queue.pop();
    }
    
    /** Get the front element. */
    public int peek() {
        return queue.peek();
    }
    
    /** Returns whether the queue is empty. */
    public boolean empty() {
        return queue.isEmpty();
    }
}

class  {
    Stack<Integer> s1 = new Stack<>();
    Stack<Integer> s2 = new Stack<>();
    
    public () {
        
    }
    
    /** Push element x to the back of queue. */
    public void push(int x) {
        s1.push(x);
    }
    
    /** Removes the element from in front of queue and returns that element. */
    public int pop() {
        if (s2.isEmpty()) {
          while (!s1.isEmpty()) {
            s2.push(s1.pop());
          }
        }
        return s2.pop();
    }
    
    /** Get the front element. */
    public int peek() {
        if (s2.isEmpty()) {
          while (!s1.isEmpty()) {
            s2.push(s1.pop());
          }
        }
        return s2.peek();
    }
    
    /** Returns whether the queue is empty. */
    public boolean empty() {
        return s1.isEmpty()&&s2.isEmpty();
    }
}
/**
 * Your MyQueue object will be instantiated and called as such:
 * MyQueue obj = new MyQueue();
 * obj.push(x);
 * int param_2 = obj.pop();
 * int param_3 = obj.peek();
 * boolean param_4 = obj.empty();
 */