剑指offer——面试题7：用两个栈实现队列

template<typename T> void CQueue<T>::appendTail(const T& element)
{
stack1.push(element);
}

template<typename T> T CQueue<T>::deleteHead()
{
if(stack2.size()<= 0)
{
while(stack1.size()>0)
{
T& data = stack1.top();
stack1.pop();
stack2.push(data);
}
}

if(stack2.size() == 0)
throw new exception("queue is empty");

T head = stack2.top();
stack2.pop();

return head;
}