package queue;
import java.util.LinkedList;
import java.util.Queue;
/**
* Description:
*
* @author elijahliu
* @Note Talk is cheap,just show me ur code.- -!
* ProjectName:EAlgorithm
* PackageName: queue
* Date: 2020/8/14 16:59
*/
public class LeetCode225 {
Queue queue1 = new LinkedList<>();
Queue queue2 = new LinkedList<>();
int top;
/**
* Initialize your data structure here.
*/
public LeetCode225() {
}
/**
* Push element x onto stack.
*/
public void push(int x) {
queue1.offer(x);
top = x;
}
/**
* Removes the element on top of the stack and returns that element.
*/
public int pop() {
if (queue1.isEmpty()) {
return -1;
}
while (queue1.size() > 1) {
top = queue1.poll();
queue2.offer(top);
}
int res = queue1.poll();
Queue tmp = queue1;
queue1 = queue2;
queue2 = tmp;
return res;
}
/**
* Get the top element.
*/
public int top() {
return top;
}
/**
* Returns whether the stack is empty.
*/
public boolean empty() {
return queue1.isEmpty() && queue2.isEmpty();
}
}