lintcode&九章算法——Lintcode No.40 用栈实现队列 ？ 待解决

public class MyQueue{
private Stack<Integer> stack1;
private Stack<Integer> stack2;
public MyQueue() {
// do intialization if necessary
stack1 = new Stack<Integer>();
stack2 = new Stack<Integer>();
}
/*
* @param element: An integer
*
* @return: nothing
*/
public void push(int element) {
// write your code here
stack1.push(element);
}
/*
* @return: An integer
*/
public int pop() {
// write your code here
if (stack2.empty()) {
while (!stack1.empty()) {
int s1 = stack1.pop();
stack2.push(s1);
}
}
return stack2.pop();
}
/*
* @return: An integer
*/
public int top() {
// write your code here
if (stack2.empty()) {
while (!stack1.empty()) {
int s1 = stack1.pop();
stack2.push(s1);
}
}
return stack2.peek();
}
}