抽象数据类型ADT一以栈为例 Out Out (LIFO)lists.Roughly,a stack is a set of objects which arrive at different points in time and are added to the set.When elements are deleted from the set, the object which was inserted last is removed first. A stack can be visualised as a pile of objects where objects can be added to or removed from the pile only from the top (see figure 2.3).In abstract terms,a Figure 2.3 Pictorial model of a stack.抽象数据类型ADT——以栈为例