Leetcode - 225 implements stack with queue

Use two queues

class MyStack {
    
    // Use two queues to implement the stack 
    // Home line 
    private Deque<Integer> deque1;
    // Secondary queue 
    private Deque<Integer> deque2;
    public MyStack() {
    
         deque1 = new LinkedList<>();
         deque2 = new LinkedList<>();
    }
    
    public void push(int x) {
    
        // First, put all the values of the main queue into the auxiliary queue 
         while(deque1.size() != 0){
    
             deque2.offerLast(deque1.pollFirst());
         }
         // take x Enter the main queue 
         deque1.offerLast(x);
        // Put the value of the secondary queue back into the primary queue 
         while(deque2.size() != 0){
    
             deque1.offerLast(deque2.pollFirst());
         }
         // At this time, those who enter the queue later x Already at the head of the team 
    }
    
    public int pop() {
    
       return deque1.pollFirst();
    }
    
    public int top() {
    
       return deque1.peekFirst();
    }
    
    public boolean empty() {
    
        return deque1.size() == 0;
    }
}

Use a queue

class MyStack {
    
    // Use a queue to implement stack 
    private Deque<Integer> deque;
    public MyStack() {
    
         deque = new LinkedList<>();
    }
    
    public void push(int x) {
    
        // How many values are currently in the queue 
        int qsize = deque.size();
        // take x Queue entry 
        deque.offerLast(x);
        // Put in front of the queue qsize Values are placed at the end of the queue 
        while(qsize > 0){
    
            deque.offerLast(deque.pollFirst());
            qsize--;
        }
         // At this time, those who enter the queue later x Already at the head of the team 
    }
    
    public int pop() {
    
       return deque.pollFirst();
    }
    
    public int top() {
    
       return deque.peekFirst();
    }
    
    public boolean empty() {
    
        return deque.size() == 0;
    }
}