代码语言：javascript复制
public class Solution {
Stack<Integer> stack1 = new Stack<Integer>();
Stack<Integer> stack2 = new Stack<Integer>();
public void push(int node) {
stack1.push(node);
}
public int pop() {
if (stack2.empty()){
while(!stack1.empty()){
stack2.push(stack1.pop());
}
}
return stack2.pop();
}
}
