package main.coding_170430;
import java.util.Stack;
/**
* Created by peterchen on 2017/5/5.
*/
public class QueueWithTwoStacks<E> {
private Stack<E> stack1;
private Stack<E> stack2;
public QueueWithTwoStacks() {
stack1 = new Stack<E>();
stack2 = new Stack<E>();
}
public boolean isEmpty() {
return stack1.isEmpty();
}
public int size() {
return stack1.size();
}
public void enQueue(E item) {
stack1.push(item);
}
public E deQueue() {
if (isEmpty()) {
return null;
}
while (!stack1.isEmpty()) {
stack2.push(stack1.pop());
}
E data = stack2.pop();
while (!stack2.isEmpty()) {
stack1.push(stack2.pop());
}
return data;
}
}