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