Leetcode - 232 realize queue with stack (design double stack to realize queue)

Queues are implemented with two stacks

class MyQueue {
    
    // Use two stacks to implement queues 
    // Main stack 
    private Deque<Integer> deque1;
    // Auxiliary stack 
    private Deque<Integer> deque2;
    public MyQueue() {
    
         deque1 = new LinkedList<>();
         deque2 = new LinkedList<>();
    }
    
    public void push(int x) {
    
        while(deque1.size() != 0){
    
            deque2.offerLast(deque1.pollLast());
        }
        deque1.offerLast(x);
        while(deque2.size() != 0){
    
            deque1.offerLast(deque2.pollLast());
        }
    }
    
    public int pop() {
    
        return deque1.pollLast();
    }
    
    public int peek() {
    
       return deque1.peekLast();
    }
    
    public boolean empty() {
    
       return deque1.size() == 0;
    }
}

/** * 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(); */